Well once I was living in a place you might call a squat. I had a bad case of crabs, and there was this nasty girl there who had been harassing my girlfriend, I must admit to plucking a few of the critters off and slipping them into her underpants drawer...
Oh yeah, back in school on a horseriding camp I did witness some guys place a sleeping year 7's fingers in warm water to produce the desired effect, so not to be outdone I managed to smear some horse crap into another's nostrils. When he woke up, he was the only one who could smell it...
And then, further back in grade 3 there was this teacher who used to harass me, real jock type and couldn't stand the fact I hated sports+i was the 'new kid'. Well he tormented me for about half a year before teaching us the subject "Phobias" and to demonstrate by example, he told us he sufferred from a phobia, arachnaphobia to be exact.
I spent the next two weeks filling a coffee jar with all kinds of spider (we have a few cool ones in australia) and when the jar was pretty much full and the spiders were all seething and eating eachother, I took it to school and at recess emptied the jar into his jacket pockets, chalk box, and desk drawers.
Well we came back to class and I was terrified, wishing I could take them all back, but too late, there were some on the blackboard and on his desk, and the guy fainted. I think that's the best revenge I ever had on anyone.
I should add that none of these events happened on April 1
ZX Spectrum 48k Issue 3, Radio shack Tape drive, Rank arena 12" T.V. set.