He associates everything with death and killing. During the Christmas Concert we had, he kept saying "Merry Killmas!" and whatnot off stage. His favorite game is Torture Game 2. He jumps on people and throws them to the ground. He's 10 years old and about 135 lbs. I'm almost 12 and I weigh 100 or so. He follows me and my friends around, even though nobody likes him. (I feel somewhat bad for him)
EDIT: I should probably mention, what should I do? He gets on our nerves and we've gotten talked to about him a few times by a teacher.