best school prank EVER is to sell ur school
find out the addy of ur school put it for sale in the papper and give them ur cell phone number and when they call tell him to come to it at like 9 am to the office tell them that they are trying to sell the school to built a new one
it works and u cant get in truble for it
u technacly did nothing wrong
(btw i did it to my high school last year it did work and it was funny as hell)