Ok here is some shit me and my friends have done.
WARRING GRAPHIC BUT FUNNY>
Roll up old crusty dog shit in a joint and watch some fool smoke it.
Ex lax in anything.Get him some where there is no can.
Pepper spray is the shit. Put it in food.Beer.Mouthwash. Ect. it is very versatile and effective!
Put 2 day old nut form a condom of a skank your buddy fucked in a hamburger.
Piss in something he is drinking in the fridge repeatedly
Milk,OJ,Pop just dont drink it.
scrub his toothbursh on the inside of a shitter.
Record him talking shit on a little tape recorder about some girls he did not fuck saying he did or some other ill shit he does not want anybody to here and play it to everybody.
IF you really want to fuck him plant drugs in his car and call the police saying he is selling them and you saw him holding a gun. Call the police and say he is making and selling crystal meth. Works if he is not your roomate.