Bloody Tampon Prank
unwrap tampons and pour some ketchup on them. Then place them all around your school campus.

This one takes alot of time and planning
Assemble an automobile in a school hallway overnite. Works best if the car cannot fit thru the space to drive out. In other words, someone else will have to disassemble the ride to get it out of there.

Mooo
Sneak onto school campus at night when nobody is there and send a cow up the stairs. Cows can walk up stairs but are unable to walk downstairs.

No Locker Access
Super glue everyone's lock to their locker. Nobody will be able to open their lockers. No books, no pens, no class today! yay!

Represent Yo Class!
During breaktime, run straight into the office and yell, "Class of 2008!! BIOTCH!!!" then run out and blend in with everyone else. 9 times out of 10 the people working in the office will have no idea who you are. Unless you are a popular student or one who is always in trouble, then obviously you are in and out of the office regularly. But make sure its the side with only the office secretaries and not the principal. Oh and you can substitute 2008 with your class.

Cheerleader Pom Pom Prank
Sprinkle some itching powder in the high school cheerleaders pom poms.

Fun With Locker Room Balls
Piss all over big bouncy balls then kick them around in the locker room while people are getting dressed.

For A Good Time Call...
After school is out and all the teachers and faculty have left, it is now time for a prank. What you do is make several copies of paper that read "For a good time call (add victim's name and number here)" then slip these papers underneath all of the classroom doors.

Yucky Vending Machine
Pour some chocolate pudding inside the drop slot of the school vending machine. When the items purchased fall down, the victim will have to pick it out of the mushy pudding. You could also use chicken fat instead.

Locker Prank
Some students lock there lockers, then do the combo but leave it one digit short, so all they have to do is turn it once. This is to save them time between classes. So just walk down the hall testing a few of them until you get 2 locks to open, then switch those 2 locks. The two losers won't be able to open their lockers.