Darth Mongoose has been using this stupid username since she was 17. Yes, she's female. Her real name is Kate Holden and she's an artist. Draws a webcomic called Fan Dan Go as well as print comics for UK small press group Indie Manga.
But the one, single thing tropers will care about is that DM is the person who drew that picture of Batman with nunchucks made from sharks from Chris Invincible Super Blog. This one