Gambol is a crime lord who appears in The Dark Knight. Gambol is the leader of the black mafia and before the events of the movie, is engaged in a turf war against Sal Maroni (the new leader of Carmine Falcone's mob.) However, due to the presence of Batman and newly-elected District Attorney Harvey Dent, Gambol allies himself with Maroni and becomes an associate of his.
He was portrayed by Michael Jai White.
When the Joker walks in on a business meeting between Gambol, Maroni, Lau, and The Chechen, Gambol hated him immediately from the start after being insulted by him, as well as killing one of Gambol's men by slamming a pencil into his eye. Gambol puts a bounty on the Joker's head: A million dollars for capturing him alive, 500 grand for capturing him dead.
Later in the movie, a gang of bounty hunters arrive at Gambol's hideout, claiming that they have killed the Joker. After bringing in a body bag with the Joker's body, Gambol prepares to pay the bounty hunters, but the Joker suddenly reveals himself to be alive and reveals the bounty hunters as his men, who kill several of Gambol's men. He supposedly kills Gambol by stabbing him in the mouth.
Gambol is later seen to be alive when he and the rest of the Mob leaders are being arrested by the GCPD following Lau's giving the GCPD his list of clients and associates. It is unknown if he is still alive following the events of the film; if he is, he is likely in prison (and possibly one of the inmates locked up because of the Dent Act).