A man who enjoys having sex with other men, but only without their consent. The more their prey wiggles and attempts escape the happier the bull queer, due to this their prey are sometimes known as 'wigglers'.
The Bull Queers cannot be classified as homosexual or gay, as Red states, "you have to be human in order for that to apply" meaning they rape their victims for pleasure and are sadists in this sense.
'The Sisters' are notorious Bull Queers in Shawshank prison. Later in the movie Bogs is severely beaten and paralyzed by Captain Hadley after he and the Sisters nearly kill Andy and after that the Sisters never target Andy again out of fear.