Middle school pranks?

Who has good middle school pranks for 8th grade that are funny

Well, Me and a couple of my friends threw water ballons at the principal, and we ciran wrapped our P.E. teachers car. =)

theres a rumor that a few years ago at my high school someone put a cow on the 2nd floor before school so it couldnt go down..since cows cant go downstairs. haha. this year a bunch of people rode scooters down the hallways..which isnt really a prank. but usually every year on the last day of school seniors get on a balcony and throw hotdogs, donuts and waterballoons at everyone.

we got out a day earlier than 7 grade and during
their p.e we threw water balloons @ them.
switched a sex ed video with a home made video
thats all I can remember

give pieces of wax paper to everyone in a class where you don't like a teacher and all of you blow on the paper to make that squeak loud noise and dont stop til the principal comes in, it's really annoying and noone can get all the blame..