Papa Doc, real name "Clarence", is the main antagonist and was a rap battler, who faced B-Rabbit in the final round. He is portrayed by Anthony Mackie.
Papa Doc first appears at the start of the movie, rap battling "Shorty Mike" at the shelter, with The Leaders Of Tha Free World supporting him. He defeats "Shorty Mike" and wins the tournament. He is later seen at the parking lot, with The Leaders of the Free World, heckling the people and B-Rabbit's Crew. Both teams of people get into a fight when B-Rabbit pulls Lyckety-Splyt's feet, making him hit his head off the car. Papa Doc attempts to use a gun, but is told to put it away by Wink. Papa Doc is later seen with The Leaders of the Free World, fighting B-Rabbit's Crew again, when B-Rabbit drives up to them and punches Lotto. He later helps The Leaders of the Free World beat up B-Rabbit for beating up Wink. Papa Doc is last seen rap battling B-Rabbit and overconfidently allows B-Rabbit to go first. In his freestyle, B-Rabbit acknowledges his lower-class roots as well as the comments the Free World members used against him in their rap battles such as Wink having sex with Alex, Rabbit being jumped, Cheddar Bob shooting himself in the leg and Future being viewed as an Uncle Tom before exposing Papa Doc's privileged background of attending the private school Cranbrook and living at home in a stable two-parent household (information Rabbit had found out at a party at Wink's house), shaming Papa Doc for trying to pass himself off as a gangster when his life was easy compared to B-Rabbit. Papa Doc, who has nothing to use against Rabbit as he has acknowledged everything, chokes and leaves the shelter with The Leaders of the Free World.
- It is learned at the abandoned house scene that Papa Doc went to a private school (Cranbrook), and that he lives with both of his parents, who are married.