In 7th grade my science teacher took off without warning about 2 months before the end of the year. The school hired a temporary teacher who was super enthusiastic but you could tell he was a bit unstable. A couple of the guys in my started messing with him; hiding the erasers, tearing single pages out of his textbook for that days lesson....little things he couldn't prove. People talked during class and pointed out whenever he was wrong about something during a lecture. Within a few weeks the teacher had given up completely and the class dissolved into free period.

About a week before the end of school, someone put a handful of silica packets in the fish tank and killed all of the fish before class. We just sit down at our assigned desks and wait. The teacher gets up in front of the class and calmly starts lecturing us on how we are the worst class he has ever taught in his life, that we're violent, terrible children willing to kill innocent animals just to torture him. He starts rambling and two students in the back of the room start whispering . The teacher THROWS A DESKCHAIR OVER OUR HEADS TO THE BACK OF THE CLASS ROOM. He starts yelling at the top of his lungs, "AAAGGGRRRHHH SHUT UP! SHUT. UP. " He picks up a small wooden chair, throws it 20' into the door, it explodes. He totally loses his mind, eyes darting around and arms swinging all over the place, yelling about how we made him go crazy and he hates teaching now because of us, that his wife is leaving him and he's all alone now and its our fault.

He storms out of the room straight to the teachers parking lot and we all watched him drive away. I heard later he lost his teaching license because he physically endangered us when he threw the deskchair over our heads. Thinking about it still makes me feel sad, especially for the fish.

TL;DR: Students tried to drive substitute teacher insane, it worked.