diversion, recreation - an activity that diverts or amuses or stimulates; "scuba diving is provided as a diversion for tourists"; "for recreation he wrote poetry and solved crossword puzzles"; "drug abuse is often regarded as a form of recreation"

dirty trick - an unkind or aggressive trick

practical joke - a prank or trick played on a person (especially one intended to make the victim appear foolish)

jest, joke - act in a funny or teasing way

strange, unusual - being definitely out of the ordinary and unexpected; slightly odd or even a bit weird; "a strange exaltation that was indefinable"; "a strange fantastical mind"; "what a strange sense of humor she has"