This was a simple but pretty damn funny prank me and some other football players did. Go buy two blow up sex dolls, put some T-shirts on with your class name et al, run them up the school flagpoles at night and cut the ropes (someone will have to climb it and tie them straight onto the top to be really effective)

The next morning the whole school got to watch our prissy little principal yelling at the janitors who could not find a ladder tall enough to get them down. They eventually had to call the fire department, Freekin hilarious