My school isn't that bad in this department, but a couple years ago, we had this kid who talked weird, yelled "don't drink coke" or something like that when someone had a soda, pranced around the school pretending to be luigi from mario, and did other weird, annoying stuff. It wasn't his fault, I think he had autism or something, but just about everyone hated him. He left to go to some special school after that year.
There IS also this other kid, who was the first kid's only real friend, and would also prance around pretending to be mario. He is still kinda annoying, but he has gotten better over the last couple years.