Zombie Halocaust

Well you start by gathering a lot of the guys in a room for a while and you choose your target(s). After you're sure you know who you want to scare just casually mention how one of the other guys got "attacked" earlier and isn't feeling well. Then leave for a while with your target(s) while everyone is getting into character (make up/torn clothes). Just to come back to a room full of bloody people eating each other.. I think this prank has a lot of shock value its hard to imagine someones reaction to a room full of gore and cannibals. Its all about the look on the victims face when they open the door and turn the corner

also we've already seen what the jackass guys look like old... I think zombie cast is only appropriate