The best prank I’ve ever witnessed was actually a prank that was played on me. It happened the summer I worked as a counselor at Victory Valley Camp.
The boys in my cabin removed all the springs from my bed frame and replaced them with twist ties. That made it strong enough to hold up the mattress, but not strong enough to hold up my fat butt.
When I sat down on the bed, I went right through the bed frame and onto the floor below. Fortunately, the mattress was still there and broke my fall.