It is a fully incdoctrinated motorcycle member. The outlaws of the motorcycle clubs/gangs. 99% of clubs are law-abiding and the other 1% aren't. These fellas do things like sew hooks in their leathers so that when cops search them they get a handful of hooks.
Howard Hughes made a movie about a 1 percenter club called the Hell's Angels.
In 1947 the American Motorcycle Association (AMA) organized a motorcycle rally called the Gypsy Tour which ended up overwhelming the small town of Hollister, California. About 50 arrests were made, mostly for public intoxication, and the AMA said the trouble was caused by the one percent deviant that tarnish the repurtation of all motorcycles and motorcyclists. Outlaw motorcycle clubs then took up the name one percenters. This incident was made famous by the 1953 Marlon Brando film The Wild One.
The Hell's Angels, Bandidos, Pagans, Outlaws and Mongols Motorcycle Clubs all consider themselves to be 1 Percenters.
Situation: A man who is madly in love with someone goes to a resteraunt with them. Head over heels in love. He goes to the bathroom where a gorgeous woman tells him she'll give him a BJ, no strings attached. Only one percent of men will turn it down.
Oh, that guy's so sweet, I bet he's a 1 percenter!
A club of about 1 percent of the male population, whom of which will actually eat a bleeding pussy
See that dude over there? He's a 1 percenter!