Attempted Exorcism?
I probably can't beat some of these but:
There was the frankly magnificent Modern Studies teacher who kept rosaries in his desk and every time a student got a question wrong he'd say a hailmary and wave them around. He also once climbed on top of a filing cabinet and threatened to jump unless he got the right answer. The resulting slam brought teachers from the floor below upstairs because they thought there was some kind of structural instability with the building. He staged class elections and when no one ran he declared us a proletarian dictatorship. An absolute legend.

Then there was the History teacher who referred to the students as "enemies" and referred to homework as "evidence". The naughty boy's desk outside the class had a sign saying "enemy outpost" on it. It is very difficult to explain his peculiarities. According to my mother, a former teacher at that school, he was an alcoholic and once fell asleep during the monumental (ten minute) journey between Kirkcaldy and Kinghorn and ended up in Newcastle. Once I wrote an essay on refugees which contained the statement "people should be allowed to live where they want to" and he told me he was coming to live at my house. A frightening man, but legendary in his own right.

Nowadays, I myself am a teacher, and probably have a whole bunch of dementations. Thankfully, none of my kids post here, as they're all Japanese.

EDIT: oh, and I forgot about the RE teacher who was the spitting image of Ned Flanders. You can imagine the jokes.

DOUBLE EDIT: and how could I forget the chemistry teacher who set fire to himself and once created a potion that spewed forth purple smoke and silver foam, thus causing the classroom to be sealed off and fumigated?. Ah, what a man.
(weirzbowski, Fri 11 Nov 2005, 15:57, Reply)