The Ageless

"Fifty years have passed. But, I do not age. Time has lost its effect on me..."

— Jack, Samurai Jack

This character is Immortal, but not because they have Nigh-Invulnerability or can regenerate any injury. They are immortal because they don't age, nor do they usually sicken. This character will never die from natural causes. However, they are just as vulnerable to injury as a normal person, and any normally fatal injury will prove fatal to them as well. This is frequently a racial trait of elves and almost always a feature of robots and vampires.

Of course, this trope can be combined with many other Immortality Tropes, particularly Nigh-Invulnerability. Characters that are extremely difficult to kill while also unable to age provides convenience for long-running series, and can also give villains credibility in terms of their threat (an Evil Overlord that can rule the Earth forever is clearly more threatening than one with average human lifespan).

Frequently overlaps with Immortality Begins at Twenty. Also frequently overlaps with immortality by Healing Factor or From a Single Cell, to the point it's more unusual to find someone with a Healing Factor without slowed or stopped aging than one with it. If this trope is combined with Nigh-Invulnerability and taken to its logical extreme, it may become Complete Immortality. It is also not uncommon for ageless beings to continue to grow in strength and vigor over their long lives.

It should be noted that what we call "dying from old age" is actually an accumulation of small illnesses and damages to the body, which result in the immune system either getting weaker or overwhelmed until it gets defeated. The Ageless is thus someone who is simply immune to these low-scale sickness though it raises questions as to where the immunity starts and where it stops.

Compare Long-Lived, Really 700 Years Old. Contrast Life Drinker, which involves stealing lifeforce from victims to maintain immortality, rather than the non-aging being an innate trait to begin with.

Examples:

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Anime & Manga

The 100 Girlfriends Who Really, Really, Really, Really, Really Love You: Kusuri's grandmother, Yaku, took a version of Kusuri's immortality drug that cannot be reverted even with the neutralization drug.
Cardcaptor Sakura, Tsubasa -RESERVoir CHRoNiCLE-, and ×××HOLiC: The enigmatic magician Clow Reed maintained his fairly youthful appearance for the duration of his several-centuries-long life with his vast powers. His apparent counterpart, the Dimension witch Yuuko Ichihara, is similarly unaging, although the reason for it in her case is because Clow Reed accidentally trapped her in a state where she's neither truly dead nor alive.
Case Closed: One of the mysteries surrounding the villain Vermouth is the fact that she has apparently not aged in at least two decades. Jodie Starling, who encountered Vermouth as a child and again as an adult, and Yukiko Kudo, a longtime friend before discovering Vermouth's true nature, both remark upon this fact. Vermouth is a Master of Disguise, but she seems to have used this to hide her lack of aging, such as by posing as her own daughter after Faking the Dead for her original public persona.
Chrono Crusade: The demons appear to be this. There's some indication that they do age, but if so it's very slowly—they look the same age even over a span of 60 years.
Claymore: The half-yoma warriors are ageless. Once it is mentioned that a warriorness never gets older, but always looks the same until she is killed in combat, or turns into an Awakened Being.
Doraemon: Nobita and the Robot Kingdom have the new characters, Queen Jeanne and her childhood playmate, Poko who's a Robot Kid. In Jeanne's flashback, both her and Poko are children, but in the present Jeanne is already an adult whilst Poko still looks like a six-year-old. Justified because he's a robot.
Dragon Ball:
- Master Roshi and his sister Fortuneteller Baba are this, both having drank from the Fountain of Youth.
- King Piccolo first mentioned wanting to wish for eternal youth from Shenron so he could rule the world forever, and gets it. The Funimation dub changed his wish to just having his youth restored (he was even stated to be holding back against Goku at first because fighting at full strength makes him age faster). According to Daizenshuu 2, Piccolo Jr. inherited this from him.
- Androids #17 , #18, and #20 are this due to their Cyborg status. #17 and #18 were captured as runaway teenage humans and turned into this by Dr. Gero's experiments (though they actually do age, just very slowly compared to normal humans), whereas Gero had his own brain transferred into the robotic #20 body.
- While Saiyans aren't immortal, their aging process is similar to the Androids, in that it's much slower than a humans (and may be even slower than 17 and 18's). It becomes noticeable in the epilogue, where most of the cast show visible signs of age except for Goku and Vegeta, who, aside from a change in wardrobe, look exactly the same as they did years ago during the Buu saga, which even gets lampshaded a few times. According to Vegeta, Saiyans stay young until they're 80, which would explain why Goku doesn't look any older than his adult son Gohan. It's a bit of a subversion though, since Saiyans still have a short life expectancy; due to their status as a Proud Warrior Race, they usually tend to die in battle more often than not, and sure enough, all the main Saiyan characters have died at least once.
Nearly everyone in Dragon Knights except the humans, as the other races seem to live on endlessly without aging past their early twenties. Garfaxy is an ordinary human who lives immortally thanks to his master and employer Kharl mixing him a pill to take every hundred years, but he also gets injured and Kharl has to occasionally tend to his wounds.
Vampires in Happiness don't seem to age in a few years or so.
Seine from Hekikai no AiON. Sadly, she's stuck forever in a 15-years-old body.
Inuyasha:
- The black miko Tsubaki from Inuyasha has used her magic to deprive other people of youth and to stay young herself. But later, her power is destroyed and she quickly ages until she is killed by this.
- Kikyo would have qualified for it if she had not been killed at the end of the anime plot. It is mentioned that because she had become an undead, she would have been immortal and would not have changed visually.
- In Inuyasha the Movie: Fire on the Mystic Island there is a magical island. There humans and youkai live together and have children together. Because the stay on this island is like a fountain of youth, the humans there do not age. At the time of the plot, however, the island was destroyed, and only six hanyou children survived, who also have not aged for at least fifty years. But because many hanyou are naturally very long-lived, it is unknown if that was the effect of the island.
Knights of Sidonia:
- The Immortal Council that rules Sidonia from the shadows, as well as the Sidonia's Captain. Apparently the Sidonia invented a drug that completely halts aging if regularly taken, however if an "immortal" stops taking this drug, they start to age at a regular pace once again. The existence of this Council and their drug is kept secret from all but the highest-ranking Sidonia crew.
- By implication, the main character Nagate Tanikaze as well due to his enhanced healing ability. Part of the reason he is constantly sent on life-threatening missions is that the immortal council objects to having an immortal who is not part of the council running around, not least of which because it could threaten the secret of their existence.
Lyrical Nanoha:
- A common trait of the Ridiculously Human Magitek programs in the series, such as the Wolkenritter, Reinforce, Agito, and the Materials. Whether or not they overlap with other forms of immortality varies, but all of them have lived since the days of Ancient Belka, with their apparent age changing only if they want it to.
- StrikerS Sound Stage X introduces King Ixpellia. She has the same child-looking appearance she has now as she did when she ruled as Garea's figurehead king hundreds of years ago, although it is unknown if she has any other form of immortality since she's kept away from the front lines.
The anime Magi: Labyrinth of Magic has the witch Scheherezade, who has hardly changed externally for over 200 years. This is later subverted, however, because it turns out that the Scheherezade the audience saw was just a kind of magical clone, and her real body continues to age, and is hidden in a secret chamber.
Edermask from Magician. Not even he knows exactly why.
Mahou Shoujo No Kareinaru Yosei: Magical girls in this setting stop aging once they retire. This is why Sasari, Lilas, and Mimi look to be about 14 year-old Shijima's age or younger, despite their actual ages ranging from mid-thirties to over a millinium old.
The Innovators, artificial humans from Mobile Suit Gundam 00 whose aging is controlled by gene manipulation and nanomachines.
Sasori from Naruto, because he turned himself into a puppet.
In One Piece, the Hobby-Hobby Fruit's main power is to turn people into toys, but it also has the side-effect of halting the aging process, effectively granting eternal youth. The current user, Sugar of the Donquixote Pirates, ate it as a child, and thus still is one physically.
- The ability to give someone both eternal life and youth is one of the main reasons why Trafalgar Law's Ope-Ope Fruit is called the "Ultimate Devil Fruit". Unfortunately, performing the surgery on someone also requires an extreme degree of medical expertise and will cost the user their life.
In Princess Tutu, Mytho never ages after he escapes from the Story Within The Story into the real world.
In Rebuild of Evangelion 3.0, this is apparently a side effect of piloting an Eva: the pilot's physical age is fixed at that point. This results in a 28-year-old Asuka still having the 14-year-old body she had in the last film. Asuka refers to it as "the Curse of Eva". In the case of Mari, this goes back even further as 3.0+1.0 reveals she's actually at least as old as Shinji's parents.^note
In Robotech, the Zentraedi apparently have biological immortality due to a protoculture-based genetic engineering, despite having a life expectancy lower than humans due to being a Proud Warrior Race and Martyrdom Culture.

In Samurai Deeper Kyo, all Mibu clan members share this trait to a certain degree. Tokito, a member of Taishirou is this due to a technique that reverses her age and stops her growth to halt the deadly disease in her body.
Sonny Boy: Time for all students that go adrift basically stops moving. The age and state in which they got to "This World" is the age they will be for as long as they exist there, for example, a girl who has her arm broken simply never heals since time has stopped for her.
In Tweeny Witches, Sheila and Eva were made ageless as punishment for letting Arusu release all the captive sprites back into the wild. Arusu didn't understand how this was a punishment until they explained that since they can't reach adulthood, they can never reach their full magical potential. Not to mention, since they're stuck as kids, they will never be able to experience adult things like getting married.
Jinbei Shishido from UQ Holder! ate the flesh of a mermaid 1400 years ago. He doesn't age but he can be injured, so he's Covered with Scars.

Comic Books

Atomic Robo is, y'know, a robot. As long as he gets repaired when he does take damage, he could keep going forever. As of the "Birthdays" mini-story, put out in 2019, he was - depending on how one factored in the whole "time travel" incident at the end of volume 8 - either 96, 109, or 239 years old and had had his entire body replaced. The vampirised version of Rex Cannon also seems to be unaging; he rants to Robo about how he toiled for six thousand years to build the dimensional rift in "The Vengeful Dead".
Astro City:
- Loony Leo, being a living cartoon, does not age.
- "My Dad" includes a passing reference to some people who never seem to get older.
Black Widow has slowed ageing thanks to an experimental formula used on her.
Blade, who has the appearance of a man in his 30s has been active since at least the 1970s, and has shown no signs of aging since due to being half vampire.
Captain America ages far more slowly due to the super soldier serum in his veins, but can die like anyone else. His ex-sidekick, Bucky Barnes, was injected with the same Infinity Formula (in fact, it was the last of it) as Nick Fury, but is as vulnerable as your average soldier.
Doctor Strange got into a fight with Death itself, accepted its inevitability, surrendered to it, and Came Back Strong. He is told that, as a result, "death may only come from without, in battle — and not from within."
The Elves in ElfQuest (except for the Wolfriders, who for most of their history were more likely to die in battle with humans anyway) do not die of old age, however, sickness occasionally happens, e.g. Krim's first child died as an infant.
Many immortals of the DC Universe, including the New Gods and the Amazons.
- Wonder Woman (1942): Amazons are only ageless while they remain on Paradise Island. Those who leave to live elsewhere start aging again, though they do so at a much slower rate than humans as Diana and Steve Trevor discover. Di still chooses to gladly live out the rest of Steve's life with him even though it is clear she will live much longer.
- In The Legend of Wonder Woman (2016) most of the Amazons have normal lifespans, outside of randomly being granted a pregnancy or two, with only the very few who are the champions of Olympians having their aging stopped which comes at a price where they have to watch everyone around them age and die and lose a significant degree of their autonomy to their patron god.
- Wonder Woman: Warbringer the reason Diana is the only Amazon aging is because she's the only one alive; the rest are serving out a rewarding afterlife after having fallen in battle. It is implied she will be the same after she dies protecting Nim and Theo and is made an Amazon by Athena.
In the world of Felarya, everyone has this due to the magical properties of the world. Unfortunately for those who come to Felarya seeking immortality, it it very easy to die there.
Hellboy came into this world looking like a baby in 1944. He grew pretty rapidly, both physically and mentally, to adulthood and hasn't shown any signs of aging since.
The Martian Manhunter, like all Martians, ages much slower than humans do, as he is several hundred years old and is still in his prime.
From the Marvel Universe, Nick Fury. His brand of immortality stems from the Infinity Formula, for which he was the lab rat during World War II (without his consent, he was half-dead at the time, having just stepped on a landmine). The formula took about a quarter of a century to work on his biology, and now, although being nominally 90 years old (born 1917-1918) he is physically in his 40s, 50s tops and will not age another day. He can however be wounded, and presumably killed; nobody really achieved that, since he's Colonel Badass, with an Eyepatch of Power. Then, it's revealed that the formula's effects have faded. Then, again, he becomes even more this.
Nick Fury's Arch-Enemy Baron Strucker, the leader of the terrorist organization HYDRA, also has repressed aging thanks to a serum.
A number of entities in The Sandman (1989), starting with the Endless (who are Anthropomorphic Personifications of primal concepts and can be killed through extraordinary means, but will be reborn as another "aspect" of themselves with a slightly different appearance and personality) on down through gods, angels, and devils, who can die because God Needs Prayer Badly but not because of aging, and down to folks like Hob Gadling, who is otherwise totally human but does not age and cannot die due to a bet between Dream and Death. Some immortals don't even know why they don't age; they just don't.
Superman: In some continuities, Superman doesn't age at all (Batman: The Dark Knight Returns), while in others he and his cousin do, but at a much slower rate than humans due to their Kryptonian heritage, and usually with white hair around their temples and just a few wrinkles to show for it (Earth Two, The Immortal Superman, Kingdom Come, Legion of Super-Heroes: Millennium, Batman Beyond); by the time Superman reaches his 70s or 80s, he looks 50, while Bruce Wayne, compared to Clark and the completely ageless Diana, is elderly with stark white hair, and no longer at his physical peak. In Superman & Batman: Generations, his aging slows exponentially as time goes on, so he looks fifty in his seventies, but maybe seventy in his second millennium.
Discussed, but ultimately averted in The Transformers (IDW). Cybertronians can live for millions of years with the known deaths either being voluntary or killed in combat. Ratchet even points out that the society as a whole doesn't really want to give up the idea that they aren't immortal. The Distant Finale of Lost Light would show Ratchet had indeed died of old age.
Wolverine's Healing Factor allows him to live far beyond the normal lifespan of a regular human. Despite being born in the late 19th century, he has the appearance, conditioning, health, and vitality of a man in his physical prime. That being said he does age, if slowly and more than one continuity as seen a future where his healing mutation is finally starting to give out on him (implied to be because the extra stress on his system because of the metal in his bones is starting to overwhelm his healing) and he's starting to show his age.

Fan Works

Abraxas (Hrodvitnon): Ghidorah is functionally immortal and has been around for billions of years. It's implied that rather than being a natural trait, this is a result of the Makers' experiments on Ghidorah when they turned it into what it is now. Although it's not confirmed for certain, Ghidorah believes that its part-Ghidorah Artificial Hybrid "offspring" Monster X might be immortal too.
Massively Multiplayer Crossover fic Blood and Revolution has various people along a scale of immortality; it seems the daiyoukai, vampires, dragons, tsukumogami, and other super-mortals fall into this category, as there are some who are millennia old and vulnerable to injury but haven't aged. This means that Sesshoumaru, Kenshin, Aoshi, Hiko, Kenji, Yukito, Shun, Hana, and Abel at least are The Ageless.
Child of the Storm:
- Doctor Strange looks about 40 odd, and has for at least 1500 years. The sequel later notes that he's actually 500,000 and this is because of the interference of the Time Stone.
- Natasha who, as per canon, is supposedly biologically immortal as a result of the Infinity Formula, and other recipients of the Infinity Formula, such as Nicholas and Perenelle Flamel. However, Word of God has obliquely hinted that it actually 'just' massively slows the ageing process.
- The Elves of Alfheim and Svartalfheim are immortal, unless killed, as are the Sidhe of the Nevernever. The Queens of Faerie possess outright immortality unless killed at the right place or time — kill 'em, vaporise 'em, whatever, they'll just come back.
- Lily as the White Phoenix of the Crown.
- Sinister hasn't aged in at least a century. Comments he makes about having travelled the Silk Road suggest he's Really 700 Years Old.
Children of an Elder God: Shinji, Asuka, Touji and Hikari are permanently stuck in fourteen-years-old bodies due to their powers stolen from eldritch abominations. Misato noticed this when she got old, but neither Touji nor Hikari aged.
The Genesis Samurais from Clash of the Elements, who haven't aged for over two-thousand years.
dead things: Harry Potter becomes this, forever looking like a 17-year-old. It's initially thought it's because Harry is the Master of Death, however, the truth proves to be far more horrifying. When he died the first time, the piece of Voldemort's soul wasn't the only thing destroyed — a part of Harry's soul was lost to death as well. For a while, nobody notices because magical people in general age more slowly than Muggles. Then, he's just parted ways with everyone by going abroad. When he comes back, only his closest friends recognize him because Harry Potter should be forty-five.
The Flutter Ponies in The Elements of Harmony and the Savior of Worlds, meaning that after the 1500 years that have passed for Equestria compared to 20 for Earth, those friends of Megan's are still around. The same is true of the Princess Ponies, but in their case it's because of the Heart of Ponyland sustaining them. Apparently so do the Bushwoolies that serve as their honor guards, and Katrina and Rep.
In Enlightenments, Wander aged up to about how old he was in Shadow of the Colossus after Dormin slipped him through the seal as a baby, then got stuck there physically. It's because he has a chunk of Dormin's soul still inside him that they can't reclaim, which is why he also has Resurrective Immortality.
In Eternal (MLP) , unicorns stop aging after a certain period. Galaxy is eons old but doesn't look older than thirty.
Fate of the Clans: Servants are incapable of aging or physically changing.
Hetalia: Axis Powers fanfic Gankona, Unnachgiebig, Unità: Like in canon, all the countries are this. Germany, Italy, and Japan all look 20 despite them being 1054, 2484, and 3284 years old respectively. That, and they are also really hard to kill.
Twilight Sparkle and Shining Armor in Harmony's Warriors, who both appear the same age in Captain Equestria (which is set in the 1940s), X-Questrians: First Class (set in the 1970s) and all the present day stories. Apparently, this is due to a serum Twilight had created.
Mobile Suit Gundam SEED Paradox: Kiryu's age is never elaborated upon, as he appears to be a man in his mid-20's, but he also appears to have maintained his appearance over the 70+ years during the Bad Future, despite the fact that he is the Carbon Human copy of Shinn Asuka.
In Neither a Bird nor a Plane, it's Deku!, K.E.L.E.X. informs Izuku that he'll likely be around for millenia due to his Kryptonian biology. But it's downplayed because he'll still grow to adulthood first.
OSMU: Fanfiction Friction: All Odd Squad agents have this ability, but the story also lampshades it, as Basil Valentine, an Enfant Terrible villain whom has connections with Todd, seeks to find the answer as to how agents never age to stop his Merlin Sickness.
In Pokémon Reset Bloodlines, Anabel has an encounter with the original Raikou, the one who was revived by Ho-Oh centuries ago. Apparently, a side effect of its resurrection made it unable to die of old age. The same is presumably true for the original Suicune and Entei.
In the Pony POV Series, anyone who becomes the Macguffin Guardian of the Rainbows of Light and Darkness becomes this trope, starting with the Moochick and Spike's most ancient ancestor Heathspike. The Moochick eventually passed guardianship to the Paradise Ponies while Heathspike died in battle, sadly resulting in Darkness falling into Tirek's hands. The Paradise Ponies only died when they willingly left and gave up their role or Discord destroyed the Element of Trust and deactivated the Rainbow of Light, though they aged naturally after that. Even the Shards of the Rainbow of Light can offer a lengthened lifespan to those who can access their power, but it seems being an ageless immortal is reserved for the actual guardian.
In Ranma Saotome, Chi Master, Ranma's guru no longer ages, thanks to her ability to convert her chi and shen into ching.
Explicitly stated to be the case for almost everyone in Sailor Moon: Legends of Lightstorm. All Sailor Scouts and Justice Champions are clearly stated to be biologically immortal (including the two title characters), and absolutely everyone was this way during the Silver Millennium.
Thousand Shinji: Shinji, Asuka, Rei and Misato never age after their ascension to godhood. Their human bodies are permanently fourteen-years-old.
In the RWBY/Hetalia crossover Weight of the World, the Remnant nation-tans are this, along with Born-Again Immortals. Once they reach a certain age they stop aging, and can live forever unless they receive a mortal wound or their Kingdom falls.
Comes up several times in With This Ring:
- Orange Lanterns can maintain their bodies in perfect condition for as long as they desire it and can keep their rings charged. Since Paul doesn't expect that he'll ever want to be dead, he anticipates having thousands of years ahead of him, if something doesn't manage to kill him first (and make it stick).
- Alan Scott has been infused with green light, which means he can keep going as long as he remains supplied with it. Unfortunately, Paul has turned his personal lantern orange, and the Guardians aren't keen to hand over a new one... Eventually, with Alan on his deathbed, Paul manages to commission a blue personal lantern, which rejuvenates Alan Just in Time, and is able to keep him young indefinitely so long as he retains hope.

Films — Animation

Coco: The appearances of the spirits of the Land of the Dead are based on what they looked like at the moment of their death, more or less; never really changing aside from cleaning up any potential wounds they may have had (like the many fractures Ernesto would have probably received by being crushed to death by a bell). As a result, Ernesto de la Cruz appears to be in his 40s at most, Héctor himself doesn't appear a day over 21 years old, while Mama Imelda and Papa Julio look much older. When the almost unresponsive and senile Coco dies, she arrives in the Land of the Dead still with white hair and hunched over, but much livelier. She can even walk again.

Films — Live-Action

Bit: As usual, vampires don't age. Duke is in her sixties but appears no older than thirty at most. Vlad, meanwhile, is centuries old and looks like he's in his forties or so.
Willie Wonka in Charlie and the Chocolate Factory is at most ten years younger than Grandpa Joe, and may be older than him, yet looks about 35. He apparently is aging very slowly, as he found his First Gray Hair a few months before the start of events in the movie. He may have discovered the Fountain of Youth while trying to create some kind of strange candy, as his counterpart in Charlie and the Great Glass Elevator did.
In the 2010 Clash of the Titans, Io was cursed by the gods with agelessness. She mentions the burden of living on while her loved ones grew old and died.
The title character in Edward Scissorhands. Justified because he is a creation by the Inventor.
The eponymous main characters of Eternals qualify as this, looking just the same as they did when they first arrived on Earth 7,000 years ago. However, even though they can't die of such things as old age, they can still be killed as demonstrated with Ajak, Gilgamesh, and Ikaris.
The Fountain: Tom Creo has lived for 500 years without aging by eating the bark of a special tree.
In Indiana Jones and the Last Crusade, drinking from the Holy Grail grants you this form of immortality. There's a downside, however: The elderly crusader explains that yes, you live forever - but only so long as you remain in the grail's sacred area. You must drink from the Grail periodically to rejuvenate yourself (hence why Indy and his dad aren't immortal despite drinking from it). Since it can't be taken from its sacred area, obviously you need to stay relatively close to that area to keep drinking from it. There seems to be an element of Age Without Youth involved as well, as the guardian is so frail he can barely stand.
In Time features a humanity that has stopped the aging process, freezing everyone's age and physical abilities at 25. Time itself has replaced money as currency, meaning that the poor live day to day, while the rich can effectively become immortal.
John Oldman from The Man from Earth says he is this, as he claims to be a 14,000 year old caveman who has survived until the current day while looking about 35 for no particular reason except he just hasn't died. He has no idea if he has a Healing Factor or not (having avoided situations where he could test that) although he does know that he doesn't scar. After initially claiming that he was lying all along, the last few minutes of the movie reveal that he is at least old enough to literally be the father of a colleague who looks to be in his 60s or 70s.
Never Cry Werewolf: Werewolves are this, as Jared is over a hundred years old and he states that werewolves do not age.
The puppets in Puppet Master are brought to life by an ancient Egyptian spell found by Andre Toulon. The spell apparently works on humans as well, but they are only invulnerable to aging. This also applies to the puppets as they can be damaged to the point of death.
We Are the Night: The vampires display this, as usual. It's neatly shown at the beginning with a montage of photos which feature Louise and Charlotte across the years (at many famous events). It ends with Louise's appearance in an 18th century painting.
Wendy: Children living on the island can stay young forever if they believe in the Mother, a kind of guardian spirit. However, they're still capable of being injured or killed. The above causes some to lose faith, which ages them.
X-Men Film Series
- X-Men: First Class:
  - Sebastian Shaw, whose energy-absorbing powers keep him young... somehow.
  - Also Raven Darkholme to a point, who ages at a very slow rate due to the ability of her cells to alter their function, which makes more sense than Shaw's immortality in the framework of the established rules of the universe.
- Logan already being roughly 130 years old in 1962, and only appearing around thirty-five, when a young Charles Xavier and Erik Lehnsherr attempt to recruit him in a bar. Forty years before he ends up actually joining the X-Men.
The fantasy-wuxia film duology, Zu: Warriors from the Magic Mountain and it's sequel Zu Warriors, have the character King Sky who remains the same age after a 200-year Time Skip.

Literature

Celica of Akashic Records of Bastard Magic Instructor is roughly four hundred years old by the time of the present. Finding out why she doesn't age is one of her major goals.
Nanahoshi of Mushoku Tensei: Jobless Reincarnation has not aged since she was teleported from Japan. She highlights just how unusual her state is by the fact that her hair and finger nails haven't grown at all since that day. However she is still able to become sick and so limits her contact with people who might carry diseases for which she lacks an immunity.
The Flame Hazes from Shakugan no Shana. As soon as a human being makes a pact with a "Crimson Lord" and turns into a Flame Haze, they do not look any older. Khamsin is a Flame Haze that looked like a child for over 3000 years.
Undefeated Bahamut Chronicle: The effects of Baptism can slow down aging, but Fugil Arcadia is special in that his repeated Baptism operations completely stopped his aging, allowing him to survive for centuries without cold sleep.
The controlling entities in Iar Elterrus' 9 Swords Multiverse are each split into Will, Power and Knowledge. While Knowledge incarnates as one of the eponymous Swords and is indestructible and immortal, Power incarnates as an ageless dragon. In contrast, Will incarnates as a mortal human, which means that every coming of the entity has the same Power and Knowledge driven by a new Will.
The shieldwatch in Aeon Legion: Labyrinth can restore its user's body by moving the user back in time to when their body was in a youthful state. This makes anyone with a shieldwatch biologically immortal. Though the user can still be injured, they can just keep restoring themselves unless their nervous system is damaged enough or their shieldwatch runs out of power.
The Alex Benedict novel Polaris has the scientist Dunnager, who was seeking a way to halt the aging process and was reportedly very close to succeeding when he mysteriously vanished without a trace and his lab burned down. It turns out he did succeed, and a number of people rendered ageless by his work conspired to keep it secret.
In the Amtor novels of Edgar Rice Burroughs, the people of Vepaja are ageless thanks to an anti-aging serum.
Area 51: As a result of their technology, Airlia can keep from aging (along with humans they've enhanced) and don't die of this.
Isaac Asimov:
- "The Bicentennial Man": Robots do not age, and can conceivably be immortal. When Andrew finds that this is the biggest obstacle to his desire to become human, he immediately schedules a surgery to correct this and dies after being recognized as a Bicentennial Man.
- "Does a Bee Care?": The alien has been living with humanity for eight hundred years, without appearing to age beyond a young adult. They are never actually identified as immortal, but they don't know enough about their species to say how long they actually live.
In Nancy Kress's Beggars in Spain, The Sleepless are discovered to be The Ageless as well due to the sleeplessness genemod turning out to unlock a Healing Factor. Considerin the Sleepless were Born Lucky to begin with, this only increases the Fantastic Racism against them.
The sorcerers of The Belgariad. People and animals who are "called" by one of the setting's gods can attain the status of sorcerer, which grants them power everywhere, not just within the boundaries of their god's territory as with mere priests, and makes them functionally immortal. They seem to choose the age they show the world -Belgarath looks old, but Polgara looks young. However, as the deaths of some of Belgarath's brother sorcerers show, they aren't even close to completely invulnerable.
In Mikhail Akhmanov and Christopher Nicholas Gilmore's Captain French, or the Quest for Paradise, all of humanity has achieved this through a one-time medical treatment called Cellular Regeneration (or CR). Usually overlaps with Immortality Begins at Twenty, since most opt to have the procedure done in their early 20s in order to forever retain their youthful beauty (another procedure, Biosculpture, ensures that everyone is beautiful). A few choose to do it in their early 30s in order to look more professional. Only recently-colonized worlds without CR equipment still suffer from aging (all except the original colonists, of course), and criminals on many worlds can be sentenced to aging (i.e. the procedure is reversible). The titular protagonist is, likely, the only person in the galaxy who looks older, as he was born 20,000 years ago on Earth before CR was invented (his biological age is closer to 2000, thanks to Time Dilation). French was the test pilot of the first relativistic starship and became the first space trader when extrasolar colonies were established. The authors delve deep into the galaxy of ageless people, pointing out that most worlds have Population Control measures in place to avoid overpopulation from people not dying of natural causes (plenty of people still die for other reasons).
Trudi Canavan's The Age of the Five: The majority of the Wilds fall into this category. The most extreme example is The Gull — the oldest of the Wilds, who has the physical body of a prepubescent child.
Caraval: Legend's performers don't age, but unlike him, can still die for real outside of the Caraval performances. Legend's goal in Finale is to demote the Fates to this status by killing the Fallen Star.
In Castaways of the Flying Dutchman part of the two castaways curse is that they no longer age, so they are an unaging teen boy and his immortal Labrador Retriever.
The Amber Royalty from The Chronicles of Amber are mostly this. They are quite tough and regenerate better than humans, but it's a very slow process (it takes four years to grow back burnt out eyes, for example). Serious wounds definitely can kill them, which happens on several occasions.
Chrysalis (RinoZ): Dungeon monsters don't appear to age at all (although most of them have short lifespans simply because they're all surrounded by carnivores). Anthony relies on this when creating the aphid queen, figuring that he'll only need to do it once if they're careful.
In the Chronicles of Thomas Covenant, the Bloodguard do not age so long as they hold true to the Vow that they made to serve and guard the Lords of the Land. For reference, the Bloodguard was founded some 2000 years before the beginning of the story proper, and many of its charter members are still in service. The artificial beings created by the Demondim (such as the waynhim and the ur-viles) also do not die of natural causes. However, both Bloodguard and Demondim-spawn can be killed violently.

In the semi-canonical sequels to Harry Harrison's Deathworld by Ant Akalandis, Jason discovers that his real parents (he was actually adopted) are this and, thus, he is as well. Additionally, Kerk becomes one after being injected with an Immortality Inducer serum developed by a secret society. When being initiated into the organization, Kerk to finds out that his "grubber" counterpart Rhys has been a member (and immortal) for years.
Damon Knight had a 1957 novella variously called Dio or The Dying Man. In the far-off Future humans have genetically engineered themselves into immortality and separated into the classes of "players" (consumers), "students" who remember and preserve the past, and "planners" who create environments and technology to make Earth a Pleasure Planet paradise. Everyone can levitate, everyone looks like a Greek god and injuries regenerate. One of the most brilliant planners suddenly loses these abilities, subsequently discovering he's going to age normally and die. His creative work reflects his experiences, and his player girlfriend has to get serious in order to understand what's happening.
In the Dolphin Trilogy, sea life doesn't age. John, Vinca, and Syn all have certain adaptations that allow them to leave in the sea and were raised by dolphins, so as long as they don't spend too much time on land, they won't age either. By Destiny and the Dolphins, John should be middle-aged, but he still looks twenty-five. In Daughters of the Dolphin, he meets a dolphin who's millennia old and remembers Ancient Greece.
In Dirge for Prester John, no one who drinks from the Fountain three times will age beyond their third visit.
In Andre Norton's Dread Companion, Kosgro observes that the people in this world do not die unless killed. Kilda contrasts this with very long-lived but still mortal aliens that she knows of.
Edgedancer (a novella of The Stormlight Archive): Subverted Lift claims she asked the Nightwatcher to "stay the same while the world changes around her", expecting this trope. Her first period proves that whatever Nightwatcher did to her, it wasn't making her unaging.
The eldrae and galari are this naturally in the Eldraeverse. It was quite a shock when they discovered other sophonts weren't, so naturally they set out to fix that small problem.
In Final Fantasy VII: On the Way to a Smile, the short story "Case of Nanaki" reveals that Vincent Valentine was made biologically immortal by Hojo's experiments. As a result, he'll live at least as long as Nanaki. However, given the events and nature of Dirge of Cerberus, it's safe to assume he can still be killed.
The Remillard Clan from Julian May's Galactic Milieu series. Each one appears to stop getting older at a different age. They have minor regenerative powers, but they can still be seriously injured or killed.
The Pillars of The Girl from the Miracles District are people whom the magic of the Miracles District has deemed necessary for the District's survival, so it responded by making them unaging.
Goblins in the Castle: Two cases, both revealed in Goblins on the Prowl.
- Fauna. While she looks about eleven or twelve, she finally admits that she's looked the same way for at least seventy years now, she doesn't know why, and she hates it. As a result of the events of the book though, she's freed of the spell keeping her from aging. Edrick guesses that since she was in the same area as he was when he used the Black Stone of Borea to perform the Spell of Stonely Toadliness that was reflected back on him, she got caught up in the backlash and became stuck at her current age, but also lost her memories and ran off into the woods. When he was turned back to flesh and spat out the Stone, she began aging again as normal.
- The sorceress Sophronia has been visiting the Baron for years, but never looks any older. She later explains that she's put herself in an enchanted sleep for about a year at a time, during which she does not age.
In L. Sprague de Camp story "The Gnarly Man" is a Neanderthal who has achieved apparent immortality after being struck by lightning . Unfortunately for historians eager to question him, he has survived for so long by aviding interseting times, "interesting" being defined as "events that can get you killed".
In Guild Hunter angels don't have a definite lifespan as they can't die naturally, and therefore tend to live a very long time (the oldest character so far, Caliane, is rumored to be at least 200 000-years-old).
In the Indigo series, may be true of Indigo and Grimya—they do not age, but even they don't know whether they can be killed by injury or disease. At one point, Indigo is seriously ill and comatose, and Grimya worries that she will remain delirious forever if the disease "kills" her. (Indigo recovers, and the question is never resolved.)
In Max Frei's Labyrinths of Echo:
- Khrebels, the pure spirits. Effectively immortal, possibly vulnerable only to the destruction of their world.
- As the mysterious World's Heart pierces the planet like a rod, two entities inhabit the ends - the Spirit of Kholomi in Echo and an unnamed entity on the opposite end. Both are probably immortal unless the world is destroyed.
- Pure-blooded elves. This doesn't extend to their offspring with other sentients, leading to dramatic scenarios and the creation of Kharumba.
- True Magic users of sufficient power, e.g. Maba Kalokh.
- Ancient Magisters, e.g. Khabba Khän.
In A Land Fit for Heroes, the Kiriath do not die of old age, though they can die of other means. Even Archeth, who is only half-Kiriath, has lived for centuries with no sign of ageing further.
In The Last Unicorn the title character is immortal but can be killed by anything from a dragon to a stray arrow.
In Lois Duncan's Locked In Time, Lisette and her children have eternal youth but not eternal life.
In The Locked Tomb series, the body of a Lyctor is preserved at the exact point in time they achieved Lyctorhood, meaning they don't get older and can't die from old age, but can die from sufficient trauma or suicide.
The Lord of the Rings and The Silmarillion:
- The elves have an unending lifespan until the world ends, have the vigor and strength of a human in his prime even when thousands of years old (though they may outwardly age under years of torture, as Gwindor in Silm), and do not get sick. They only die if slain or by wasting away from grief. Even death isn't always permanent; after an elf's spirit has spent some years in the Halls of Waiting, if they have thoroughly repented and learned from any sins they committed, they get re-embodied — this, however, is not an inherent power but a grace provided by the Valar (the godlike archangels of Arda).^note Although this may actually just be extreme toughness. Apparently male elves grow beards in their "third stage of life". This may correspond with a human's "middle age". In other words, they may have a biological clock much like that of a human...just slowed down to such an extent that no elf will die of old age before the world ends. Immortality, after all, is NOT a blessing in this setting.
- Orcs, who are (usually) understood as corrupted elves, are hinted in a few places to be similarly ageless, but this is not explicitly stated.
- Ainur (Valar and Maiar) are ageless within the world, and will continue in perfect youth until the end of the world. Their youthfulness however is because of the fact that they can make new bodies at will. Their bodies (called "fanar") can age after whatever manner is normal for that type of body. It's just that the spirit inside doesn't leave the world, and can inhabit a new body.
  - The Istari, or wizards, are understood to be five Maiar sent to Middle Earth with the appearance of wizened men, with the intent that they provide counsel, not become rulers. According to the Tale of Years they'd been in Middle Earth for two thousand years by the time of the War of the Ring but remain apparently ageless, though small signs of the passage of time are noticeable (longer beards and eyebrows, for example). Despite their guise as men their longevity sometimes got them mistaken for elves (the real etymology of the name "Gandalf" is "elf with a [magic] wand", as Tolkien pointed out).
- Ents are just as long-lived as elves, as Treebeard explains to the hobbits. They have a tendency to get sleepy and tree-like, but they never age.
- In the Blessed Realm of Aman, all animal and plant life remains in a state of youthful adulthood after reaching maturity. The Hounds of Oromë, which may or may not just be dogs, are as ageless as elves.
- Dragons can be killed but they never die from natural causes. Tolkien originally wrote that dragons generally will live "practically forever" unless killed, and this is what it says in the published book. However, in Tolkien's revisions of The Hobbit that were never completed, he changed it so that dragons are stated to be Long-Lived with a lifespan of 5000 or 1000 years.
- Tom Bombadil, who calls himself Eldest and was there before all living creatures and indeed most of the world as later beings knew it, is of a completely unguessable age physically and generally acts gleefully unaffected by the world's cares (though he shows his grasp of responsibility and justice, as it pertains within his carefully demarcated realm, on several occasions). His wife Goldberry, though not as old, seems similarly ageless.
In Lost Voices, girls turned into mermaids spend their whole lives at whatever age they were when they were transformed. Catarina is one of the oldest at about sixteen, but some are as young as five or six. Girls younger than that are referred to as larvae, and they aren't taken in by the tribe, but left in the ocean until they're eaten by orcas. Luce is horrified by the prospect of leaving infants to die, but Catarina explains that larvae are impossible to protect for very long, especially since they'll never grow old enough to care for themselves, and they just attract predators.
Lythande: Pilgrim Adepts are immortal so long as they keep their Dark Secret that's the key to their powers, but can still be physically killed.
The Immortal Vermin of Bruce Coville's Magic Shop series are this type. In Jennifer Murdley's Toad, Bufo, the first of the Immortal Vermin to appear, says he can be killed, but barring such an incident, he will live forever. Jerome and Roxanne, the youngest of the Immortal Vermin, inform the protagonists of The Skull of Truth and Juliet Dove, Queen of Love: of their status as "killable, but otherwise undying". (It may also be mentioned in the updated version of The Monster's Ring.)
In Maureen Birnbaum, Barbarian Swordsperson, for reasons that are never explained, Maureen does not age at all while off on her adventures. Time passes at the same rate for her as it does back on Earth, but her old friend Bitsy Spiegleman gets older, gets married, and has kids as the series progresses, while Maureen remains a teenager. This is a source of puzzlement to everyone, but Maureen is too busy barbarianing to fret about such details.
The Mer age a few years per century up to a certain point, and then stop. They never grow old - they can only be killed by illness or injury, and they rarely get sick.
The Merman's Children: Merfolk age at the same rate as humans until they reach adulthood, and then stop. Undersea life is so hard and dangerous that many die young, including three of Vanimen and Agnete's seven children, but the lucky ones live for centuries. The downside is that merfolk are The Soulless, so when they die they simply disappear instead of going on to Heaven or Hell.
In Dmitry Glukhovsky's (of the Metro 2033 fame) The Future, humanity has discovered the "aging vaccine" at some point during the 22nd century. By the 25th century, aging is a thing of the past, but population size is strictly controlled. Special soldiers are grown and trained for the purpose of maintaining the size of the population and combating terrorists and ideologists of the so-called Life Party.
The Lord Ruler from Mistborn. He can store up youth and health by using Feruchemy for later consumption, making him both ageless and virtually impervious to injury. In the end, Vin kills him by tearing away his storages - so she almost literally rips the vitality out of him.
- Also the kandra, at least as far as we know. At the very least they live to be hundreds of years old without adverse effects. They are also rather tricky to kill by injury due to their ability to close wounds using their shapeshifting powers, the best way to kill them seems to be acid. That said the oldest among them do seem to be considerably less active than the younger ones, although it's unclear if they're actually any physically different or simply choose to stay put.
In the The Mortal Instruments and The Infernal Devices, warlocks are this. They do not age after reaching adulthood, but are not significantly more resistant to physical injury than humans. This is also implied to be the case with the Fair Folk. Vampires are a little closer to Immortality, as they possess Healing Factor, although they can still be killed, most obviously by sunlight.
Mother of Learning: The "Immortal Eleven" aren't truly immortal; Oganj the dragon mage is known to have killed two of them. Rather, they are a group of expert alchemists who gained notoriety when they succeeded in brewing potions that stopped them from ageing. Silverlake is one of them; she doesn't reveal her exact age, but it's a 3-digit number and yet she looks merely middle-aged. She next wants to invent a potion that will restore her body's youth, though she's in no hurry.
In Sergey Lukyanenko's Night Watch (Series), the Others are pretty much this (or rather, they age extremely slowly), as long as they have access to Power. If their access is taken away, they become, effectively, human. Child Others continue to age normally until they are adults, at which point the process slows down to a crawl. It's a little different for witches, due to their Closer to Earth status. Outwardly, they use magic to maintain a youthful, beautiful appearance. Underneath, though, they eventually start looking like dried-up husks who would crumble to dust if their magic access is cut off.
Nightfall (Series): All vampires are immortal and nearly invulnerable although they can still die by staking, fire, or sunlight, and serious wounds or lack of blood can weaken them.
Dragons in The Obsidian Trilogy are this. They do not age or get ill, but they can be injured and killed. If they chose to bond with a human or elven mage, they will also die when their bondmate does.
Percy Jackson and the Olympians:
- Calypso has lived on a desert island for over 3,000 years without really getting older. This was justified by the fact that she was not a human but a Titan. Towards the end of the plot of The Heroes of Olympus she leaves the island, however, and is transformed into a human being. As a result, she has lost most of her strength, which is why she is likely to age thereafter like any other human being.
- The huntresses of Artemis have this. When the young girls swear their lives to the goddess, age can't kill them. Only if they fall in battle, or break their vow to swear off boys and romantic/physical relationships in general, can they die.
Dorian Gray from The Picture of Dorian Gray had this because his painting aged and took the physical effect of his sins instead of him, though No Immortal Inertia kicked in when his Soul Jar was destroyed. Not only his physical appearance was immune to aging; his body didn't incur the ravages inflicted by his hedonistic lifestyle.
A Practical Guide to Evil:
- This is the case for Named villains. After coming into their name, they stop aging and are theoretically immortal- although in practice, the constant conflict of Good vs. Evil or their own megalomanic schemes ensure they die at about the same age as their heroic counterparts.
- Elves do not die of age either - the elves living in the Golden Bloom are still the same racist pricks who slaughtered the former inhabitants some centuries ago (which is good for them, since they have been cursed not to have children since that massacre.)
- Very, very powerful Drow who learned the right secrets are also functionally immortal, but their Chronic Backstabbing Disorder and the amount of Night powering this keeps these numbers small. By contrast, less powerful drow have a fixed lifespan, always dying at 60.
In Vadim Panov's Secret City:
- Nav', although mortal and with some WeaksauceWeaknesses.
- Divine Lords of Tat'. While vulnerable to both regular and magical harm, their power levels and personal brands of Taking You with Me which inflict damage on geological scale serve as a strong deterrent.
- Possibly the Asura, although their surviving contemporaries, Nav' and Tat', are unreliable sources of information at best.
- The last couple of Osara, king and queen of the common Os'. This is at least partially caused by Nav' meddling.
- "Flying Dutchman's" crew - they are ageless and maybe truly immortal until they either voluntarily leave the ship or fulfill the Curse Escape Clause.
In H. P. Lovecraft's The Shadow Over Innsmouth, the Deep Ones are said to live forever "except they was kilt violent".
In The Silent War The Redcloaks, the setting's empowered demon slayers, don't age nor suffer sickness or infections. Protagonist Katja is still only a teenager, but her mentor is her 130's (and apparently considered something of a teenager herself, by the true elders).
Everything on the planet Iego in the Star Wars Expanded Universe.
Norna-Gest from the Old Norse Tale of Norna-Gest gains this kind of immortality by exploiting the Exact Words of a norn's curse.
In The Third Millennium: A History Of The World 2000 - 3000 A.D., The Emortals and Starpeople achieve temporary biological immortality through genetic engineering and the rejuvenation procedure; most who don't die by accident will eventually die from a failed rejuvenation, but they typically remain youthful to about age 400 - 500.
Conrad Nomikos from This Immortal has stopped aging somewhere in his mid-20s, most likely due to mutation caused by radioactivity, and keeps reinventing new identities for himself at somewhat regular intervals to hide that fact. His inner monologue implies that he can die from unnatural causes, but will live forever otherwise. This comes in handily in the end when Tatram Yshtigo judges Conrad to be morally upright and long-lived enough to take control over all affairs concerning planet Earth.
In Jack Vance's To Live Forever, life-extension treatments exist, but are only given to those who do something of cultural significance. A select few do something so great that they are given permanent immortality. This Amaranth status also grants them 5 clones they can use as backup in case of accidental death. It also grants them the honorific "The".
Tree of Aeons: Quite early in his new life, Matt receives a system message that "Trees are immortal if they do not get killed." Since he's quite hard to kill, he ends up watching years and decades pass, friends come and go, and the cycle of heroes and demon kings repeating over and over...
The Immortals of Tamora Pierce's Tortall Universe books, which include creatures from centaurs to dragons. First seen in (wait for it) The Immortals quartet.
The Tough Guide to Fantasyland: Elves and Dark Lords live forever unless killed.
Viceroy's Pride:
- The original purpose of the nanites that Dan is given to help him with magic was actually to make a bunch of rich conspirators immortal. Dan doesn't focus much on his supposed immortality, being more worried about being given untested super-advanced medical technology that apparently hasn't actually had a successful use yet. It does work on him, but from then on his life is so dangerous it's extremely unlikely he'll ever have a chance to truly enjoy his extended lifespan.
- The elves don't seem to be actually immortal, but considering that they are known to live tens of thousands of years, it's unclear if they can die of old age, or if it's just inevitable for something else to catch up with them.
In Void City, human thralls of vampires ranked Master or higher don't age; a gift which comes in exchange for being magically bound to obey the commands of the vampire who controls them.
Warbreaker:
- One of the perks anyone able to gather enough of the local magical energy, Bio-Chromatic Breath, to reach at least the Fifth Heightening (approximately 2,000 Breaths) gets. People with less than that age more slowly, but the Fifth Heightening is when it stops completely, and they're immune to poison and disease to boot (although still vulnerable to physical injures). The main issue is that each person is born with a single Breath that can only be given away willingly. 2,000 Breaths would be an incredibly valuable hoard, to say the very least.
- The Returned are people who died and came back with a Divine Breath, automatically putting them at the Fifth Heightening (thus making them immortal). They no longer need to eat or drink, but instead consume a single Breath each week. If they can't get more Breath from an outside source, their Divine Breath is consumed, killing them, so many don't live beyond their first week. They are still just as vulnerable to injury as anybody else, as poor Blushweaver discovered.
In Watersong, the sirens do not age, remaining eternally young and beautiful.

Live-Action TV

12 Monkeys:
- The serum required to survive using the Project Splinter time machine seems to render the user as this, or at the very least alters how the aging process works. Ramse, for instance, spends decades Trapped in the Past without visibly aging, only for a later medical exam to show that parts of his biology have in fact aged at a normal pace.
- The Pallid Man and Olivia, the Co-Dragons of the Army of the Twelve Monkeys, also don't seem to age at all, leading to speculation that they're time travelers as well. Season 2 reveals that it's actually because they're the biological and cloned (respectfully) children of one of the Messengers, and share in her genetics, which were engineered specifically to work this way.
Kenneth Parcell on 30 Rock is strongly hinted to be immortal and unchanging in appearance.
666 Park Avenue: Drake resident Danielle hasn't aged for at least sixty years as part of her deal with Gavin. However, she's unaware of it; it seems he regularly wipes her memory.
Lorien from Babylon 5 introduces himself as the First One — the very first sentient being ever born in the galaxy. His entire species was originally ageless, though they could be killed by injury or disease. But somewhere along the line, "the universe decided" that living things would need to grow old and die if there was to be any true progress, and future generations aged as normal.
Buffy the Vampire Slayer has powerful sorcerers and witches who apparently can use magic to be stale. Two special examples are the aunts of Giles.
In the Speculative Documentary Can You Live Forever?, an experimental procedure allows Adam Savage— yes, the one from MythBusters — to retain a youthful constitution into old age.
"I was 132 years old. I didn't feel it though. In, fact, I felt awesome."
Doctor Who:
- Ian and Barbara Chesterton, the original companions, were stated in the show's spinoff The Sarah Jane Adventures to have not aged between the 1960s and the 2010s.
- The Doctor zig-zags this as most of his incarnations never appear to age despite spending centuries in that particular body, with the Tenth Doctor claiming to Rose that part of the reason he lets go of his companions is because it pains him to see them age when he doesn't. The First and the Eleventh Doctors are the only numbered incarnations to have become elderly, the First being introduced as an old man with a full lifetime behind him and the Eleventh spending over 1200 years in that form before nearly dying of extreme old age. The implication is that Time Lords do age, but it takes an absurd amount of time (and is undone when they regenerate, anyway).
- The retconned-in War Doctor is mostly shown as an old man near the end of his time, but the partial reflection at the beginning of this incarnation in "Night of the Doctor" is that of a much younger, digitally de-aged John Hurt. It's unclear how long the War incarnation lasted.
- In Series 9, two characters are transformed into ageless immortals: Ashildr, a 9th century Viking girl, and Clara Oswald, with the latter observing onscreen that she no longer ages or has a heartbeat after being biologically frozen at the moment just before she would have died. She still has to go back to her death eventually to avoid a universe-ending paradox, but she has an indefinite amount of time to put it off.
- Downplayed in both Doctor Who and Torchwood with Captain Jack Harkness. He initially thought he wouldn't age, but after a long time started to notice he was getting wrinkles and his hair was graying, so he was just ageing very slowly. As in "looks the same age after spending 2000 years buried alive" slowly. The Doctor Who episode "Last of the Time Lords" reveals that Jack may be destined to transform over millions of years into a creature known as the Face of Boe, which is little more than a giant head.
Both Henry and "Adam" from Forever (2014)... sort of. They do not age, however they can be killed, but only with the weapon that caused their original "real" death. Henry's agelessness even becomes a subplot point when it's shown in flashback that his normally-aging second wife Abigail is uncomfortable being seen in public with Henry because she is afraid people will think he is either her son or a hired escort. Also, Adam tries to kill Henry with the same musket pistol that originally killed him, but Henry still comes back to life, possibly negating that hypothesis. One downside is that an immortal can become paralyzed and stay this way for years until someone kills him (Henry does this to Adam to neutralize him in the final episode).
In Good Omens (2019), Angels and Demons do not age, at all. Aziraphale and Crowley look the same in the present day as they did 6000 years ago, when they first met (except for their period-appropriate clothes and hairstyles, of course). And when Angels' and Demons' human bodies are killed (discorporated), they simply get another one and return to what they were doing. The only way to actually kill an Angel or a Demon is to use Holy Water (Demons), or Hellfire (Angels). It's the same in the book the show is based on.
In Haven, mysterious human-like beings from another dimension like Mara, William, and Agent Howard have not visibly aged in centuries. However, it is pointed out that they can be wounded and die.
The Immortals on Highlander stop aging at the time they suffer their first death and become immortal. This can lead to unique turns such as Kenny who is 800 years old but forever stuck in the body of the ten-year old boy he was when he first died.
The Partially-Deceased Syndrome sufferers in In the Flesh are mentioned in Series 2 to have not aged a single day since the Rising. One teenager derides his friends hopes for an undead-living relationship with his classmate as being impossible, since he'll still be 16 when she's 60.
Ace Ukiyo of Kamen Rider Geats is physically 21 years old. Chronologically, he's almost 100 times that age, having been participating in the Desire Grand Prix since 1 Anno Domini, easily making him the oldest Terran Rider in the entire franchise.
Lost's Richard Alpert made a deal with Jacob about 150 years ago, gaining immortality in exchange for becoming a leader to the people of the island. His reasons for asking this? Being afraid of going to hell for accidental murder.
New Amsterdam (2008): John Amsterdam has physically been 35 years old since the 1600s. In the pilot he suddenly dies when it seems like he might have had an encounter with his true love, but he resurrects and walks out of the morgue.
Odd Squad: Oprah looks 7 years old physically (at the start of Season 1, at least), but is really much older than that — about 231 years old, according to "Odd Beginnings: Part 2". In that episode, it's revealed that as the Big O, she has the ability to control her aging and can grow older as she wishes, but chooses to remain her current age to keep being employed with Odd Squad. It's unknown whether this is a perk of being the Big O, or if it's an ability exclusive to her.
Once Upon a Time: Rumplestiltskin seems to have this, as he hasn't aged a day while Gepetto has aged from a young boy to an old man. It's generally a very bad idea to try and kill him by normal means.
Pushing Daisies: Ned's dog Digby was resurrected when Ned was nine years old. Digby is still alive and well in the present, well beyond the usual lifespan of a Golden Retriever, and hasn't aged a day since Ned brought him back. At one point Ned states that Digby is still at risk of being killed via accidental means, such as getting run over again. Word of God says this is a side effect of Ned's resurrection power and that Chuck, Ned's love interest who he also brought back, is similarly immune to aging.
Shadowhunters can have a variety of this with vampires, warlocks and other supernatural characters.
- Raphael looks in his 20s but a vampire pushing a century. He still watches over his "baby" sister, Rosa, who's now a senile 78-year old woman. When she finally dies, Raphael looks over an album of photos of them over the years, Rosa aging while Raphael stays the same.
- Warlock Magnus is over 1400 years old but maintains a very youthful appearance. It becomes a tearjerking moment when he shows lover Alec a box of mementos from dozens of men Magnus has loved over the centuries and this is the only way he can remember them all.
- Subverted with the millenia-old Seelie Queen who first shows up as a ten year old girl. However, she later takes on the form of a woman in her early 20s before going back to her child form.
Seelie Queen: Different outfits for different occasions.
Flint, in the Star Trek: The Original Series episode "Requiem for Methuselah", was born on Earth in 3834 BC as Akharin ("A soldier, a bully, and a fool...") who was fatally wounded in battle and just didn't die. Over the years, he claimed to be Solomon, Leonardo da Vinci, and Brahms, among others. Once away from Earth's "complex fields", he began to age normally.
The Twilight Zone (1959): Walter Jameson from the episode "Long Live Walter Jameson" was granted this form of immortality in Ancient Greece by an alchemist. He says that he came close to death many times over the centuries due to injuries and disease, "but never close enough". At the end of the episode when he is shot, he begins to age rapidly as he dies until he is nothing but a pile of dust.
The Twilight Zone (1985): In "Welcome to Winfield", the people of Winfield stopped aging in the late 19th Century after The Grim Reaper Chin Du Long grew to like them and arranged to spare them from death.
Wynonna Earp has Doc Holliday, who made an unspecified deal with the Stone Witch in order to gain eternal life and vitality in order to survive his tuberculosis. However, he makes a point of explaining to Wynonna that he can still be wounded or killed otherwise.

Myths & Religion

Irish mythology: The Tuatha De Danann, the gods of Irish myth, are immortal in a similar manner to the Aesir and Vanir of Norse myth. They live indefinitely unless killed. Also like the Norse gods eating the Apples of Idun, the Tuatha De Danann maintained their immortal vigor by periodically drinking "The Feast of Goibniu" a divine beer that restored the youth and vitality on those drank it, and/or by eating the meat taken from Manannan Mac Lir's immortal pig.
Norse Mythology: The Aesir and Vanir are immortal in this way, so long as they continue to eat the Apples of Idun.

Pinballs

Golden Logres has the Fisher King, the King of Castle Carbonek who has been guarding the Holy Grail for centuries.

Radio

Dimension X's "Dwellers in Silence": The robot Hathaway family isn't capable of aging. They don't know how long they will last, but they do not grow old like Dr Hathaway (their creator) does.

Tabletop Games

Champions: "Longevity: Immortal" is an option for the Life Support power.
Changeling: The Lost: Joining the Office of Vizierial Council is one of the only ways in the New World of Darkness to achieve this without major Immortality Immorality. However, the agelessness comes from a magically binding Pledge for the Vizier to be The Good Chancellor to their Changeling rulers — who are usually a quartet who take turns leading and tend to see the others as enemies — and is retroactively revoked if they fail in their duties.
Dungeons & Dragons has two variants on this trope: Monks and Druids (as well as some Prestige Classes) gain the Timeless Body ability, which causes them to no longer age physically (or at least do not get any penalties for aging) until they drop dead when they reach their species' maximum age (thus invoking the Old Master trope). Two races, Elan and the Killoren, have no maximum age and will visibly age to a certain point (venerable age for Elan, old age for Killoren) but never die of old age. Combining either race with either class leads to this trope. There's also an epic feat that adds half your maximum possible age to each age category (a stadium where your character gets visibly older), which has the same effect on them.
Eberron: Warforged might be this. Nobody really knows for certain, as they're an artificial race that was created only a few years ago. But none of them show any signs of aging so far, and that's a good thing, too, since they can't reproduce due to being constructs and no new Warforged are being made anymore.
Earthdawn and Shadowrun: Dragons and Immortal Elves have this quality. Dunkelzahn was apparently tens of thousands of years old, and some immortal elves were thousands of years old in Shadowrun.
Eclipse Phase: This is implied to apply by default to biomorphs other than Flats (baseline humans), but even that is beside the point when people can be restored from backup if their body dies. Superseded further in that resleeving is used for applications as mundane as travel, not just to provide a recovery option to the recently deceased.
GURPS uses Unaging (15 character points) for basic agelessness. This means only that the character will never grow older or die of old age, it confers no resistance to disease or harm. Full biological immortality additionally requires immunity to disease and ingested poison (20 points) and Regeneration (regular, radiation only -60%) (15 points) for a total of 50 points. Other forms of immortality require additional powers. Unkillable 2 is common (100 points, can be discounted by achilles heals or hindrances). Radiation tolerance, upgraded regeneration, regrowth, immunity to all metabolic hazards and upgraded regeneration can create nigh invulnerability. Resurrective immortality (Highlander, Ajin) can be pulled off unkillable 1 (highlander, with beheading achilles heal) or unkillable 2 (ajin) and regeneration (between normal and fast for highlander, extreme for ajin) with a custom -60% limiter that makes regeneration work only when a character is dead (-5x HT or fails a death check). Ajin would also have regrowth (only when dead -60%).
Mage: The Ascension: The "Unaging" Merit lets any mage become this with a minor investment in the Point Build System. As to why it's minor — it only negates the mage's aging, and in the Crapsack World setting, mages have much more pressing threats to their wellbeing.
Mutants & Masterminds: Agelessness is a single point (immunity to aging). For full biological immortality, add immunity to disease, poison, and environmental radiation for three more points. Plus an additional point to make these innate (won't get nullified/neutralized by power theft, power nullification cell or collar, etc..). Full biological immortality runs you 5 points. Stronger forms of immortality up to and including Nigh invulnerability or complete immortality will cost you much more - regeneration, immortality, more potent immunities. Immunity to all toughness + will + fortitude resisted effects will run you 140pp with nearly nothing leftover - very boring character to play and unlikely to be approved by a GM. Innate regeneration 20 and immortality 20 will cost an additional 80 points — 220 points will get you a complete immortal nigh invulnerable god.
Planebreaker: Darli Yos is about three hundred years old, and lived many years elsewhere before coming to Timeborne. She stopped ageing after accidentally triggering life-extension magic meant for an emperor. That emperor is long dead, but descendants still sometimes hunt Darli down and attempt to get revenge for her theft.
Ponyfinder: Ghost ponies cease physically changing on reaching adulthood, and don't have maximum lifespans. Instead, elder ghost ponies are eventually drawn deeper and deeper into the mysteries of the Ethereal Plane, and one day simply vanish into the depths of its swirling mists and never return.
Rocket Age: The Europans, along with any other species with the Immortal trait, do not age, but they are still vulnerable to physical injuries and disease.
Wearing the Cape: In Barlow's Guide to Superhumans, Iri Pegason, an ultra-class telekinetic with a hallucinogenic drug induced breakthrough guided by choldhood fantasy, is forever frozen at the age of sixteen, the age that he was when he experienced his breakthrough, and has been a homeless perpetual teenage stoner for ten years or so. Iri is ageless and biologically immortal (will not die from any natural cause) but is not fully immortal — he is not nigh invulnerable and can die from violent or un-natural causes.
Warhammer 40,000: Common humans and the Tau are the only ones that don't have a means to keep young.
- The Imperium has juvenat treatments which can keep the user young indefinitely, and can even treat people to keep them juvenated at a particular age within the span of adulthood, and some senior authority figures prefer to keep an outward appearance to give an impression of wisdom and experience. Thing is, juvenats are quite expensive, so only members of wealthy noble houses, highly valued or highly placed civil servants, and Inquisitorial personnel have easy access to them.
- Techpriests of the Adeptus Mechanicus replace all of their fleshy bits with machine parts over time, not to mention that they have access to the Imperium's limited cloning technologies. Provided they don't get killed, they're on record for living for millennia.
- The Space Marines' Astartes physiology will keep them somewhere between young and middle age, in theory, forever. In practice, their bodies take strains and wounds that even their bodies can't keep up with indefinitely, and they do age, albeit very slowly. Except for some of the most senior members of a chapter, their age is more told not by wrinkles and lines, but by scars and bionics they accrue over the years.
- Eldar will live a natural lifespan of roughly 1000 years. However, they will live longer as they get stronger psychic potential. As each of them is a natural latent psyker, they simply need training to expand and refine their psychic powers, and extend their life cycle. The most famous/notorious Eldar Farseer, Eldrad Ulthran, has been alive (and apparently young) since the Horus Heresy, nearly 11,000 years ago, and there's no telling how long he was alive before then.
- Dark Eldar are notorious for their means of keeping them alive. They have to go on slave raids to abduct prisoners, torture them to death, and drink in their suffering and their souls to rejuvenate themselves to youth. There are also a number of other, more creative ways of keeping a prisoner alive to extend their suffering. However, whether it's because they have extended their lives far beyond even the natural Eldar lifespan or because of their ghastly means of doing so, the oldest Dark Eldar actually do look every bit as decrepit as one would expect thousands of years old beings would look like. They're just able to hide it with a lot of Magitek based Glamour. One of the reasons the Dark Eldar hate psykers and daemons is because they can see the Dark Eldar for what they really are.
- Orks are like lobsters, in that they never grow old, they just keep growing and keep getting meaner. Theoretically, they could live like that forever. However, since they're constantly fighting, even when they come in the hundreds of thousands, Orks rarely ever get past thirty, if that. There was once one Ork Boss known only as "The Beast" which was apparently the size of a building, and it had tusks as thick as tree trunks and kicked Nobs around in the same way they kicked around Gretchin. Emperor knows how old that thing was.
Warhammer Fantasy uses this trope as part of its 'immortal enemies hiding in wilderness' motif, with many of the forces of Disorder especially making use of this.
- As in 40K, Daemons of Chaos and Chaos Warriors tend to be ageless, the former because they're literal demons and the latter due to frequent exposure to the Realm of Chaos near the north pole where Reality Is Out to Lunch. Chaos Champions can become centuries old in real-time and still carry on their bloody business, like Sigvald the Magnificent.
- Dragons are, as a general rule, ageless, though they tend to sleep for longer and longer as they get older until they one day simply stop waking. It is said that all the dragons of the world will awaken again for the Final Battle of the world.
- The Dragon Ogres are, as a species, completely immune to aging, having bargained for immortality with Tzeentch during the arrival of Chaos. Apparently the cost for this was to make the whole species sterile; more philosophically inclined Dragon Ogres consider this to be Tzeentch's idea of a joke.
- Similarly to 40K, greenskins appear to be ageless. Certainly, there are no old examples of either, but that may come down more to their extremely violent lifestyle. At least in one continuity of the setting, the goblin warboss Grom the Paunch has survived for at least a century with no signs of aging, much to the consternation of his Arch-Enemy Eltharion.
- All lizardmen (except skinks) are ageless and will only grow larger and Stronger with Age. The skink character Tehenahuin is also immortal, apparently a side-effect of being The Chosen One of Sotek.
- Forest spirits of all kinds are ageless and persist as long as their forests do. The oldest spirit, Durthu Oakheart, is well over 10,000 years old.
World Tree (RPG): Zi Ri do not experience any form of natural mortality — they live until something kills them. They can expect to live forever, and indeed quite a few of the original generation made by Hren Tzen are still alive and well.

Video Games

In Battleborn, those who have become immortal via the Jennerit's Sustainment process do not age as well as gain an immunity from natural illnesses.

In a rare event chain that requires supernatural events be turned on, a character can attain this in Crusader Kings II's "The Reaper's Due" DLC. They will never age and can laugh off even plagues like The Black Death. Unfortunately, they're likely to slowly lose limbs and sanity over the years, and with the lovely people they're surrounded by, the risk of violent death remains quite high.
Dark Souls has multiple types of beings that are The Ageless. The Everlasting Dragons, the Lords and the Gods, and undead that can maintain their humanity.
Dragon Quest V: When the heroes find Dr. Agon, he's sitting in a mine cart trapped in an endless loop for 20 years; and still he has the appearance of a man in his 30s. Later it is revealed he is the Zenithian Dragon in human form.
The Elder Scrolls:
- Though there are many regional variations on their appearances and powers, vampires typically have this trait throughout the series. However, there's a catch: if a vampire goes too long without feeding, they'll go irrevocably insane.
- The Sload, a race of "slugmen" native to the "Coral Kingdoms" of Thras to the west of Tamriel, have no known age limit or size to adult Sload. One story tells of an "Elder Distended One," who seems to serve as some sort of leader to the Sload. It is said to be "impressively corpulent" and regurgitates some unknown substance that other Sload then "eagerly consume."
- The Nerevarine of Morrowind becomes this, along with having Ideal Illness Immunity, as a consequence of having Corprus but getting negative effects cured. Technically, anyone with the Corprus disease has these traits, but unless the negative effects are cured, it also leaves you completely insane with a nasty case of Body Horror.
- Dragons in Skyrim are this, being divine Aedric entities with Resurrective Immortality (unless their soul is absorbed by another dragon or a Dragonborn). In most cases, dragons even get Stronger with Age. Paarthurnax in particular has been waiting on top of the Throat of the World for Alduin's return since the Dragon War many thousands of years ago. The most powerful weapon that can be used against them is a Thu'um shout which forces dragons to briefly know what it's like to be Mortal, Finite, and Temporary. In gameplay it robs them of the powers unique to dragonkind: flight and the use of the Thu'um.
Ghouls and Super Mutants in the Fallout series. The former can still suffer from mental degeneration, which results in them becoming zombie-like "feral" Ghouls. Some Ghouls even remark that their supposed "immortality" is more like this, as they still age (albeit very slowly). Some of the latter are mentally unstable. The Nightkin of the first generation are because of their prolonged Stealth Boy use. And the second generation is because of their post-War mutation(s) to the radiation, and the Forced Evolutionary Virus' reaction to this. The Super Mutants found in the Capital Wasteland and Commonwealth in fact become Stronger with Age, but at the cost of their sanity.
- Comes up as a huge plot point in Fallout 4. Kellogg, the man who kidnapped your son is able to maintain his youth due to extensive cybernetic augmentation. Perceptive players may be able to notice when trawling through his memories that he was a ten year old boy when the NCR was formed in 2189, meaning by the events of 4 he would have been over a century old. The whole point is to show just how the Sole Survivor's perception of the flow of time has been altered by being a Human Popsicle - by the time they finally meet their son Shaun, their baby boy is a sixty-year-old man with terminal cancer.
- On a related note, Fallout 4 also fleshes out more of the in-series lore concerning the Institute's Synths. Being androids, it's explained that Synths cannot age any more or less than the age that they're designed to resemble. However, some other information in-universe implies that Synths do age, but at such a slow rate compared to ordinary people that it's ultimately negligible.
Sheng Qian-qian, one of the heroes from The Gladiator, is revealed late in the game to be three hundred years old and have lived past two dynasties, thanks to her upbringing in an ancient monastery.
Sol Badguy, the Bounty Hunter Anti-Hero Antagonist of the Guilty Gear games, is implied to have been born sometime in The '80s. Given the time-frame, that would make him easily 170 years old. But that can't be right, can it?
The Forerunners in Halo. The highly advanced armor systems every Forerunner wears provides continuous medical service, both physically and mentally, allowing the wearer to live pretty much forever. It's unknown exactly how old the oldest Forerunner was before their species' destruction, but some are mentioned to be over 12,000 years old. The Didact is technically 100,000 years old, but that may be due to the Cryptum he was trapped in, and not necessarily just his armor systems.
- The Forerunners also experimented with Type V immortality, but that was one of the few pieces of technology they actually couldn't properly master.
As revealed in Hyperdimension Neptunia V, any CPU can get killed through any means, however they won't ever age at all.
- The CPUs can start aging if they get their powers stolen, like what temporarily happened to Vert in Hyperdimension Neptunia Re;Birth1.
I Was a Teenage Exocolonist: If Sol gets close enough to Artificial Human Sym for the Modular Epilogue to include his "Where Are They Now?" Epilogue, said eplilogue notes that Sym never ages.
The Dragons in The Legend of Zelda: Skyward Sword are implied to be this way. You find the Thunder Dragon's remains in the present, and travel back in time to find out he's sick and dying. After healing him in the past, he's simply absent in the present, but does show up for the song, so he likely just changed residence instead of dying.
The krogan in Mass Effect are implied to be this. Wrex and Okeer are both over a thousand years old (Wrex was born sometime after the start of the Krogan Rebellions, while Okeer was apparently alive and fighting during the Rachni Wars), and neither show even the slightest sign of keeling over from old age any time soon. The only reason that most krogan rarely do reach advanced age is because their homeworld Tuchanka is a Death World, populated by Thresher Maws and fierce infighting between the various clans. The life expectancy for krogan who go off-world is just as low, due to many hiring themselves out as mercenaries or joining criminal gangs. Andromeda brings us Drack, who is over 1,400 years old and noted to be exceedingly old even for a krogan. It's mentioned in passing he is reaching the end of his life (meaning he has another century or so left), but it's not clarified whether that's because the krogan do have a maximum lifespan or whether the sheer number of injuries he's accumulated are finally catching up to him.
Being a Mortal Kombat champion grants this type of immortality until the next Mortal Kombat tournament, which is usually a generation away from the previous one. When Goro won his first tournament, he stopped aging and lived 500 years before his winning streak came to an end at Liu Kang's fists.
As the Ultimate Life Form, Shadow the Hedgehog is ageless, most likely due to the genetic material contributed to Project Shadow by his biological "father," Black Doom. The reason behind this was that Shadow's creator, Professor Gerald Robotnik, wanted to study immortality and use the fruits of his research to find a cure for his granddaughter and Shadow's surrogate sister Maria, as she was terminally ill and suffering from a fatal disease known as NIDS (Neuro-Immuno Deficiency Syndrome).
In StarCraft II: Wings of Liberty, Stetmann's research on the Zerg sample reveals that the Zerg do not suffer cell degradation, meaning they can't die of old age. Stetmann refuses to even consider figuring out a way to grant this ability to humans, since the results would likely be Body Horror. Instead, he figures out how to apply it to metals to make self healing buildings. However, Starcraft II Heart Of The Swarm clarifies that all organisms age, including Zerg, even if they don't die from it.
Any Immortal Leader from Stellaris. They can still suffer from accidents, and die the "normal" way (assassinated by The Mafia for Governors, anomaly results and/or being shot down for Scientists in charge of a Science Ship, and dying in battle for Generals and Admirals.)
The robots in Stray do not age conventionally nor can die of old age due to being able to replace the body parts that wear out. However, they can suffer such gruesome fates as being Eaten Alive by Zurks or getting forcibly rewired until their original personality is lost.
The 27 True Runes of Suikoden grant this type of immortality, in addition to various abilities based on the aspect of existence that the True Rune governs. Bearers like Ted have lived for 300 years. However, another commonality of all the True Runes is their nature to attract conflict. This usually cuts the lives of the bearers short. Arshtat Falenas, for instance, lasted only 2 years.
Rosalina from the Super Mario Bros. series is the powerful guardian of the cosmos, and has physically remained a young woman for centuries or more. Despite this, she can still be harmed by common enemies when she's a playable character.
In Sword of the Stars, the Liir cannot die of old age. Instead, they become bigger and more powerful. Their population is kept in check by the Square-Cube Law; eventually, their mass becomes too great for them to survive even in an aquatic environment and they are crushed to death by gravity. The Suul'ka are Liir elders who went "screw gravity" and teleported themselves into space.
The angels from Tales of Symphonia. The Cruxis Crystals halts the aging process, which is why Mithos Yggdrasil still looks more or less exactly the way he did 4000 years ago. Even Expheres slow the aging process considerably, in addition to the basic skill upgrades they give. Presea even brings up the possibility of a world of exosphere-preserved Immortals to Lloyd, who gently reminds her that they're Powered by a Forsaken Child.
Touhou is filled with beings like this. Lunarians separated themselves from the impurity of the Earth, taking them beyond age and death; they're still vulnerable to death however, which is why they still quarantine themselves from Earth, and when Kaguya obtained Complete Immortality they exiled her. Magicians, both the Mage Species and human mages who become Magicians, don't age and don't need food once they learn the relevant magics, but are still Squishy Wizards. Youkai in general staying the same for centuries is extremely common, though despite being exceptionally durable they aren't indestructible.
The Turing Test: The virus found in Europa turns anything it infects into this, thanks to its ability to repair DNA damage.
The Archons in Tyranny are implied to be incapable of dying of natural causes. Evil Overlord Kyros is also stated to have been actively conquering Terratus for more than a hundred years, implying the same. Oddly enough, the Archons are independent wizards conquered by Kyros, implying that most fairly powerful magic users become The Ageless.
Undertale:
- Boss Monsters are a powerful subspecies of monster with a more powerful soul than most other monsters. These monsters age to maturity and then stop until they have a child, at which point they begin aging again as their child reaches maturity. Boss Monsters who never have children will never grow old, and even those who have gotten older will still live forever if their child has died. The only Boss Monsters still alive are Asgore and Toriel, and both are confirmed to have lived for more than a century (if Bratty and Catty's wording is to be taken seriously and not as hyperbole, they are actually a millenia old or older).
- Downplayed with normal monsters. They don't need a child to age, but still have a long lifespan. Gerson proves this, as he's confirmed to have fought in the Great Offscreen War (which was implied to have happened a millenia ago, once again by Bratty and Catty).
- In Deltarune, an Alternate Universe to Undertale, the two Boss Monsters in question are aging, due to having a still alive son, who's college age. On the flipside, the newly-introduced Darkners have been implied to be at least a century long if Jevil is to be believed.
Warcraft:
- Night elves used to have this form of immortality, before sacrificing it to save the world from the Burning Legion. All the elf and troll varieties appear to have this trait to uneducated humans, because of their Healing Factor. Thus they don't get wrinkles or grey hair as they age: and their active lifestyles tend to mean they maintain their physical fitness too. However, they do slow down both physically and mentally without help from magic and can die of old age (it just takes a really, really long time for them to do so). Draenei may also have this form of immortality (Velen is explicitly stated to but this may only be a trait of the Triuumvirate), or they may just be extremely long lived. Demons also have this type of Immortality (at least one quest states that at least some of them have Type IV as well).
- Dragons, or at least the Aspects, seem to be undying as well. Or were until they recently had to relinquish it, anyway.
- Various types of magic can be used to make a person effectively this trope. However, it generally comes with complications...like being enslaved to cosmic powers, or going completely insane. Certain very powerful individuals however, have managed it.
- Orcs might or might not be this trope. Even they don't know. This is because their planet was constantly trying to kill them even before they blew it up, and because of their "Honor Above All Else" mentality. They are considered elderly by the time they're thirty. Varok Saurfang, who was considered practically ancient by orcish standards at the time of his death, could not have been more than fifty five. No orc in living memory however, has actually shown physical signs of aging (Gul'dan's decrepit appearance was due to fel magic overuse, not age).
Xenoblade Chronicles 3: It's subtley hinted that those from before the intersection of Bionis and Alrest have immortality, or at least cannot age. This is likely a result of Aionios being frozen in time, with those not reborn through Origin having their ages similiarly frozen in time. This is different from the form of immortality that Moebius have, as while they are able to exist for eons over time the can suffer the effects of aging, with the prime example being Triton, who has become a Scatterbrained Senior despite his immortality. Those known to have this ageless existance include Shulk, Rex, Melia Antiqua, Nia, Panacea Reid, Linka Cassini, and the seven legendary Nopon, which includes Riku.

Visual Novels

Juniper's Knot: Fiends don't age.
Major/Minor gives us "The Immortal King" Velasquez, who is this to the citizens of Terra. Apparently time is not always in sync on other words, so theoretically one could find a world where time moves incredibly slow for them, thus making them practically immortal.
In Umineko: When They Cry, Ikuko Hachijō is implied to be this and is a bit of an enigma in the series in that regard. In the epilogue, which takes place in the 2030s, she must be easily 70 years old but is every bit as youthful as when she had found Battler/Tooya, which was in 1986. Ange even points it out, saying that "rather than being good with make-up, she had a mystique around her, as if she was an immortal who didn't age".

Webcomics

A BETTER PLACE: Hannah has used her powers over creation to halt her aging process, staying a child for a hundred years until the events of the main comic.
Consolers: The companies don't physically age (120+ year old Nintendo being a good example) and won't die from simply aging or other natural causes. However, they can still die, usually from going bankrupt or otherwise going out of business - they still have to make an effort to "keep themselves alive" as a company. However, as long as they manage to stay in business they'll still stay alive even for hundreds of years.
Drowtales: The fae races, such as drow, light elves, and faeries, remain perpetually youthful and strong provided that they live with enough other fae to generate a surplus of mana. Otherwise, they will suffer from mana deprivation and will start to age much like humans do. One audiobook explains that fae do in fact have a finite natural lifespan (implied to be somewhere around 1000 or upwards), but most don't live long enough to ever get close to it, making them effectively this trope to any humans they might run across. It's explained by Quain'tana that the older you get, the more mana you need to sustain your body — thus the very old become increasingly trapped living in cities so there are enough fae around to sustain them. Diva'Ratrika, the Imperial Queen, was most likely aged in the four digits and was essentially stuck in her fortress.
El Goonish Shive: Elves are the offspring of one human parent, and one Immortal parent. While they can be killed, they don't physically age past early adulthood. However, the one elf we have seen so far (who has lived in the same city for decades) hides this by using magic to appear elderly in the presence of muggles.
Homestuck: Due to a combination of the natural immense longevity of sea-dweller trolls and her latent Life powers, the troll impresses is functionally immortal — she will never age and wither, and will remain youthful and strong until and unless killed by violence.
A Magical Roommate: Oracles live for as long as they want. They can be killed by outside forces, but otherwise, they will live until they decide to die — unlike their counterparts, Sages, who do die of old age.

Tower of God: Pretty much everyone is this. The spiritual energy that suffuses the Tower means that anyone who can use that energy well enough to become qualified to climb it will also stop aging. Some have been climbing for centuries.
Trying Human has the resident Herr Doktor, Glassner, who's stopped aging due to contact with alien tech.
Yokoka's Quest: Spirits don't age in the conventional sense — they don't even have an age listed on their bio pages.

Web Original

In Dis Acedia every denizen in Dis does not age after having their souls Claimed by Lazarus no matter their species. The main protagonist is shocked to learn that his human ally, the knight Sol, has been alive since the Crusades and hasn't aged a day. This immortality is also mitigated by everyone being capable of dying to some good old violence, which Dis has in spades.
The eponymous beings in The Hidden People are this by default, immortal and eternally youthful. Absolutely a given, since the beings in question are The Fair Folk and implicitly stated to be the Aesir and Vanir mentioned in the above Mythology entry. The only Hidden that actually looks old became that way because of a curse leveled on her.
The guys of make up a guy do not age, and cannot die unless they are killed by illness or injury, or when somebody discovers their quirky "guy" trait.
In the Para Imperium universe most Federation citizens have nanomachines that prevent aging. Outworld exiles aren't so lucky.
The Runepunk podcast series from RPGMP3 features a character called Kieron Hammerfall, an Andari Runecaster. Kieron is imbued with momentous arcane power, as well as the durability of a dry twig. He's a member of the Andari race, which means he's blessed with immortality (barring any unfortunate accidents - which, considering his virtually non-existent toughness, could involve being knocked over by a stiff breeze or something). Furthermore, Andari and technology don't mix.
Lee Marvin of Welcome to Night Vale is an odd example. He turns 30 years old every day, and has done so since Night Vale was founded.
In 17776, an unexplained event on April 7th, 2026 turned the entire human race into this trope. People no longer age or die of disease, but they can no longer reproduce either-the human population has remained the same ever since the last babies conceived before the event were born and grew to adulthood. It's still possible to die from accidental or intentional violence, but the widespread deployment of nanomachines to negate any potiental hazards has made that a non-issue.
In the world of Taerel Setting, the kin'toni are mostly this, but this trope is averted by the Kha'orm Kin'toni Clan, who die of radiation-related health effects after about 75 years.

Western Animation

Adventure Time:
- Princess Bubblegum has been around for centuries and still looks the same. While she usually appears about 18, this "age" (and the maturity that comes with it) depends on her physical size.
- Marceline is immortal due to being a vampire, and seems to have been a teenager for about a thousand years. (Note that even if she wasn't a vampire, she'd still be very Long-Lived due to being half-demon).
- The crown made Ice King look like an old man when he was quite young, and when the power of the crown was taken away, a thousand years later, he reverted to his previous age as Simon Petrikov then rapidly started dying of old age. He took care of Marceline when she was a child, and according to Death himself, may well live to see the Sun blow up.
Beast Wars: While too much of G1 is forgotten/sketchy for most of its players to still be around, Ravage still is.
It's unknown if imaginary friends in Foster's Home for Imaginary Friends can suffer health problems or die from old age, but time never changes their appearance. A photo album showed the main imaginary cast looked identical at least twenty years ago, which made Herriman question the point of taking pictures in the first place.
In Jackie Chan Adventures anyone with the Dog Talisman is immortal. But as Ratso points out it can still hurt.
Mortal Kombat: Defenders of the Realm has the rule that the champions won't age until the next tournament -but then dark forces disrupt the tournament cycle. Liu Kang discusses that, if the tournaments don't resume, the current champions won't age ever.
My Life as a Teenage Robot: Since she's a robot, Jenny will remain a teenager forever. She is capable of maturing mentally though.
My Little Pony: Friendship Is Magic: Equestria's Alicorn God-Princesses appear to be this, if not completely immortal, being well over a thousand years old. According to Luna in The Journal of the Two Sisters, the sisters are just very Long-Lived. Star Swirl the Bearded, on the other hand, was this thanks to an age reversal spell he created and used on himself.
Regular Show On the condition that he performs a ritual in the woods every year on his birthday, Skips will never die of old age. However, in "Skips' Story" he explains that it doesn't mean he's invulnerable to things like lack of oxygen. He also nearly dies from stress in "Skips' Stress".
In Rose Petal Place, Rose Petal and her friends won't die of old age, but can still be hurt or killed.
During the fifty year Time Skip between seasons 4 and 5 of Samurai Jack, Jack realizes he stopped aging when Aku sent him to the future. Aku himself is frustrated at this since waiting for him to die of old age is no longer an option. Jack himself is even more frustrated because he doesn't want to spend eternity stuck in a Bad Future.
In Steven Universe, each Gem is Born as an Adult and never ages, and can only truly "die" if their gemstone is shattered (and even then, the shards remain partially conscious, knowing nothing but their desire to be whole again). Steven being half-gem seems to have made his aging erratic and somewhat affected by his state of mind, though he still manages to look like a human his age by his late teens. Word of God suggested Steven would only die of old age if he chose to.
Most incarnations of the Transformers, and good luck with the fatal damage.

Real Life

This occurs in Real Life among several different species. Biologists know this phenomenon as biological immortality and negligible senescence. Jellyfish are the most well known example. Cracked's 6 Unassuming Animals That Are Secretly Immortal lists others, such as lobsters and turtles. Their populations are kept in check anyway since nature offers plenty of ways to die outside of old age (for example, lobsters can die of exhaustion while molting because of the metabolic energy required, especially for larger specimens).
Scientists in Real Life have been attempting this type for a very, long, time, such as Aubrey de Grey (co-author of Ending Aging, published in 2007). Many believe that humans will eventually attain it. There are a substantial number of people who believe that the first bicentenarian-to-be has already been born, and is possibly already an adult.
Actuarial tables indicate that if all natural causes of death were prevented, the current rate of unnatural causes (violence, suicide, accidents, etc.) would end up pinning the average lifespan of a real life Ageless at around 2,000 years. Of course, that's not taking into account behavioral and technological changes that would go along with such a long lifespan.
Red dwarfs^noteNo, not this one, the smallest and less massive and luminous hydrogen-fusing stars, are the best example of this trope the Universe offers. Not only do they fuse their hydrogen at a miserly rate, those stars are, unlike more massive suns like Earth's, entirely convective, meaning that they have access to all of their nuclear fuel. This translates to them being able to shine for up to more than 10 trillion years, and thus preserving, during most of their lifetime, the aspect they've had in their youth (or rather their infancy).
Cancers and tumors don't age, which is kinda the problem. Normally, bodies start breaking down after a while because cells are "programmed" to only recreate themselves a set number of times. Once that number is up, your cells stop replicating and you run out of the ones you need pretty fast. Cancer cells, on the other hand, are mutated cells that keep replicating. And they never stop. The problem is that it never stops expanding, which has a tendency to fuck up other, more important parts of your body.

Examples:

Video Example(s):

Quite Literally Unaging

Alternative Title(s): Biological Immortality, Ageless Immortality

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Quite Literally Unaging

The Ageless

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Examples:

Video Example(s):

Quite Literally Unaging

Alternative Title(s): Biological Immortality, Ageless Immortality

Previous

Index

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Quite Literally Unaging