Brian Dennehy is a celebrity who appeared in South Park: Bigger, Longer & Uncut during the song, "What Would Brian Boitano Do?". His lines parody those of Brian Boitano in the original Jesus vs. Santa cartoon. He later reappeared in the background of the Season Fourteen episode, "200", as one of celebrities suing South Park.
Dennehy has short blond hair. He also appears to be very stocky. He wears a brown suit, light blue tie, white shirt, and a white "dress" shirt. In "200", he had been redesigned in many ways. His blond hair has turned grey, he is wearing a black tie, he is shorter, and has a redesigned face.
Brian seems to be very calm, not showing the slightest bit of anger when the boys indirectly insult him in South Park: Bigger, Longer & Uncut. Despite not affected from the insult, he was still with many of the other celebrities brought together by Tom Cruise to sue South Park and get Muhammad.