I did this toilet paper prank at school in front of the class on the teacher.
Bring a chocolate bar to school and in the middle of class ask the teacher if you can go to the bathroom. If she lets you go, make sure you have the chocolate bar with you.
Rub the chocolate onto your hand. The thicker the better! Then, when you come into the classroom show your hand to the teacher and class and say "There wasn't any toilet paper." When I played this prank, it got a big laugh.
You can even pull your nose up a little while holding your hand out for her to see.