Buck was a male nurse who repeatedly raped Beatrix Kiddo while she was in a coma, in addition to selling her "services" to male clients.
Deal with JasperEdit
He recommended her to Jasper shortly after she awoke from her coma. After being paid, Buck detailed what Jasper could and could not do to Beatrix while he was alone with her, giving him 20 minutes to rape her. After Jasper is left alone with Beatrix for a few minutes, she kills him.
When Buck returns, Beatrix subdues him and interrogates him as to Bill's whereabouts, having remembered his being present at some point during her coma. Buck, not knowing who Bill was, was unable to answer her, at which point Beatrix remembers Buck saying "My name is Buck and I'm here to Fuck." Enraged at the fact that Buck more than likely raped her while she was in a coma, Beatrix kills him by smashing his head between a door and its door jamb. Searching his pockets, she finds the keys to his automobile, which he dubbed the Pussy Wagon. Beatrix used this vehicle to seek out and kill the members of the Deadly Viper Assassination Squad and Bill.