Timmy Zombie
Term used by older gamers to describe immature or younger gamers who will be caught going Away From Keyboard (AFK) or Away From Controller (AFC) to try and farm credits in online multiplayer video games. The name Timmy is a reference to the South Park character of the same name. Zombie comes from the fact that the character will literally stand there like a zombie for much if not all of the entire game, then move on to haunt another multiplayer match set up automatically by the game.
I was playing Halo Reach last night and came across two Timmy Zombies in Firefight.