Sophomore year I had two classes with the same teacher, Theater Arts and Speech. They were always eventful.
Well, one time in theater arts we were learning stunt moves like rolls, sword fighting, and like jumps and tucks. We were doing a basic forward roll and the teacher couldn't get any volunteers, so I offered to go. So they gather around and I get in the middle of the floor and go to roll (I've done it plenty of times) and misjudged when to tuck, and about cracked my skull on the floor. The whole class thought it was hilarious, and the teacher about panicked.
This next one's kinda gross, so I'm putting it in spoiler.
[spoiler]There was all sorts of weird stuff in the theater arts room, because she had her One Act people in there all the time planning for competitions and stuff. People in the groups switched, and one time I got to be in the 'punk kids' group. There was this kid in it named Nick, he was crazy. Nick wasn't known for his intelligence, and one time on one of the shelves there was this little tub of body cream. We were all speculating what it could be, and for some reason got on the subject of what it might taste like.
Nick wasn't paying attention, so a guy named Jordan pretended to eat some. Everybody reacted like EEEEEEW! and Nick asked what'd happened, and we said Jordan ate some. Nick asked what it tasted like and Jordan told him coconuts (hee), so Nick got a big glop. He eyeballed Jordan and asked, Dude, did you really eat some? and Jordan said yeah, so Nick takes this HUGE bite. The face he made was so funny.

We all were like OMG what if it was the teacher's butt cream? and he ran over to the trash can and almost threw up. It wasn't very nice, but it was hysterically funny.[/spoiler]
Another time, we were really bored and the teacher didn't have anything planned. Nick was discussing how the teacher NEVER seems to notice whether he's there or not, so we all decided to experiment. He snuck into the door that leads to the theater, which wasn't visible to anyone but our group 'cos of how the class is arranged (It's almost all couches, no desks). He just stood there for about fifteen minutes, and nothing happened. But the teacher was wandering around, so he couldn't sneak back in.
So he stands there, and suddenly just takes his shirt off and poses. We're pretending to hoot and whistle, so he starts to do a jig and dance around, and takes off his shoes and disappears. We see pants getting swung around, and he leans around and grins at us. He sticks a leg out and waggles it, and by this time we're all dying. The teacher notices and kinda eyeballs us, but Nick hides each time she comes by. Finally he rushes his clothes on, and as he comes out the teacher spots him and is like, What on EARTH are you doing? We're all ROLLING, and he's like, Uhh, nothing! And sits down really fast. It was great.
Then, in speech. I was the youngest student there..usually it's all seniors, sometimes a junior, but I was the only sophomore (they all thought I was a freshie). And one time I'd been messing with a senior and he bent my thumb all back, so I bit his hand when he wouldn't let go and got labeled a vampire (vampire..feh! I like fur, thankyou). So they already thought I was a bit off. But one time we were discussing ways to mess with the teacher's head, and somebody came up with the idea of me weirding everyone out.
So, two bucks richer, I walk over to the teacher's desk and talk with her a while. And as I'm walking back, I lean my chin in and say, "Quit TALKING to me Satan, GOSH!" in this growly, angry voice. My group is rolling, but everyone else in the class goes DEAD still and just stare. There's a silence as I rush back to the couch and bury my face in a book, and for almost the rest of the class nobody said a word. It was so funny...nobody said a word to me outside the group for at least a week, they were so terrified. Although after that, on occasion, I did get some remarks along the line of, 'Don't make her mad, she'll sic her little friend on you!'
That reminds me..freshman year, I hung out with some girls who were openly into Wiccan/different types of witchcraft. They got harassed a lot by the other students, because our school was extreme Biblethumper. It was outright animosity. In gym, the students would throw different balls at us when the coaches weren't looking, trying intentionally to hit us (yet for some reason balls aimed AT me never hit. Sarah and Krystal liked walking with me. Coincidence?) Anyway, one time one breezed past my nose and just missed. I was really annoyed, so I picked it up and acted like I was doing some kind of spell on it, and hurled it back at the kids. They scattered like bowling pins, and at the end of class when the coach told us to clean up, NOBODY would touch the ball. Coach had to get it, himself. Paranoia~!
In eighth grade I made a girl cry...she harassed me a lot, and told me I was going to hell because I was at that time an 'atheist', so once I told her that if she didn't stop, I would have a friend cast a spell on her. She believed me, and burst into violent tears, and I was taken outside. The teacher asked me why I said it, and I just said I was kidding, and explained how the girl harassed me all the time. I was told not to say things like that, and sent back to class. As insane as it was, the girl never dared say anything to my face again after that. It wasn't very nice, but neither was she.