Overview
GamemasterAnthony's Birthday refers to a forum game which occurs on February 28th wherein users role play as characters from all forms of media including film, video games, television, books and comics, to have a "party" for an internet user who goes by the handle GamemasterAnthony.
Background
On February 28th, 2008, forum poster GamemasterAnthony wrote that it was his 33rd birthday, which meant that "every character from every game, comic, cartoon, TV show, movie, and book reality come in with everything for a HUGE party" (shown below). The post likely appeared on the Badgame forums. GamemasterAnthony's real name may be Anthony Bault, as his account on forum-hosting site ZetaBoards links to a Fanfiction.net account listed under the name.