adjective

departing from usual or accepted standards, especially in social or sexual behaviour.

deviant behaviour

aberrant,deviating,divergent,abnormal,atypical,untypical,non-typical,anomalous,digressive,irregular,non-standard,nonconformist,rogue,perverse,transgressing,wayward,strange,odd,peculiar,uncommon,unusual,freak,freakish,curious,bizarre,eccentric,idiosyncratic,unorthodox,exceptional,singular,unrepresentative,distorted,twisted,warped,perverted,backasswards,bent,kinky,quirky

noun

a deviant person or thing.

killers, deviants, and those whose actions are beyond most human comprehension

nonconformist,eccentric,maverick,individualist,exception,outsider,misfit,fish out of water,square peg in a round hole,round peg in a square hole,oddball,odd fish,weirdo,weirdie,freak,bad boy,screwball,kook,wackadoo,wackadoodle