First go to a warthog accesible level and get a freind to play in multiplayer then get one guy against the wall and the other person to run it into him full speed if done at a really really fast speed buy some means there will be blood splattered on the wall, and he will have been what appears to be cut in half pulling back on the warthog will make the person disappear but they must be dead...though...can you run somebody in like that and still let them be alive???