A classic.

Go to a farm and try to steal 2-3 chickens.
If you steal 2, write the numbers 1 and 3 on them and unleash them into the school.
They will be looking for the third cicken forever, since they found the first and third.

If there are 3, write 1-3-4. etc. etc.

^^^
Retarded and not really all that hilarious.

Fill your teachers desk drawer up with something that either smells rank or is a bitch to get out.

I.E. An old teacher of mine from jr high looked like sugarbear from those Sugarcrisp commercials so me and a friend filled all of his desk drawer, filling cabinet, and briefcase up with 15 or so boxes of Sugarcrisp cereal.

Or, you could study hard and get good marks in the classes that you have with teachers you hate and prove that you are not going to turn out to be a failure at life, regardless of if the teacher tries to fail you or not.

I suggest you superglue things to your teachers desk. Or superglue things on the school ceiling.

Get all of your friends to bust loads all over every sqaure inch of the room

your all rookies, pffft i was expelled from my high school for grand theft security golf cart. me and a buddy of mine broke into the school one friday night drove the security gaurds golf cart out of the auto tech shop and cut open the fence with tin snips and drove to a party on the other side of town. then we walked back to the school (the battery to the cart went dead) and slept in the school. after this i realized GED was easier than alternative school and so thats my prank, incarceration, and how i graduated a year before my class.

You know the soap dispensers well at my school the have the ones were you push it at the front and its gray and white and holds the pink soap. Well at the bottom in the back thees a button and you push it and the top comes up. Well me and my friends are gonna open it and put something in it we were thinking piss or something really disgusting

Not the funniest, but I wrote the Fight Club rules in permanent marker on the white hallway walls for fun. I used to be obsessed with that movie.
It was fun
my buddy threw a whole hotdog at a teacher in the lunchroom and hit her in the back of the head. that was pretty priceless

my high school has seperate buildings for most classes. so senior year during night im gonna come and chain all the doors shut so no one can get in. originally i was gonna do it during class but then i thought what if there was a fire and all my friends died lol.