i watch my skoolmate ryan run into doors on purpose. he doesn't get hurt, but when teachers pass by he fakes the pain and the teachers are like omg! one of the funniest things i ever watch.
oh and at lunch, oh man! i sit with other skoolmates and we get the disposable salt shakers from the condiment counters (like where they have ketchup and mayo and stuff). we punch holes in the bottom with nickels and dimes and we bring it back to where the condiments are. so when someone tries to salt their fries, the salt starts leakin out from the bottom lol. their reactions are so funny. oh and we also pull out chairs as someone's about to sit down (without holding any food tho, cuz otherwise that'd be so messed up).
once, in school, i threw a cupcake top at a girl that was kinda far away. i didn't think it'd hit her, but as it soared, it just got closer and closer to her until it hit her in the chest and she screamed and fell down from shock.