This is pretty tame, but my friends and I used to leave ransom notes around our OSSM Calc/Physics classroom for what we thought of as the peppermints that were owed us. (There was a candy dish at the front of the room that we always refilled, but was mysteriously depleted when we came back in the mornings.)
We taped pieces of paper over the clock, on the windows, on doors, desks, chairs, lab tables, and the floor saying things like “Bring us more mints…or else!” We even wrote one in dry-erase marker on the mirror in the bathroom.
Other times, we unscrewed the back supports of certain students’ chairs, and rigged a table to collapse. It just so happened that someone in the afternoon class tossed their backpack and two 44-oz. Pepsis on the table before its death. They waded through a sticky, sugary flood of Biblical proportions for three hours.
Our Physics teacher was shot in the crotch with a 1/4" ball bearing launcher.
We put a note from an imaginary ‘Angie’ in the pocket of our married Calc teacher’s jacket. It said something like “Hey, Sweetie! We had a great time together. Call me!” and the phone number of a girl at a local University.
There was a “magic cart of Physics,” a.k.a., a box-moving cart, that we used for momentum and inertia ‘experiments.’ Most of the experiments ended with some volunteer skidding across the concrete floor.
We parked cars in the storage space on the way to the classrooms, hit the ‘big red buttom’ that turned out to be an alarm, and left a note on the outside door saying that class had been moved to another building, so nobody showed up.
I miss OSSM!