Gambol (portrayed by Michael Jai White) is a minor character in The Dark Knight. One of Gotham City's leading mob bosses, he was once at odds with the city's other major crime families before the arrival of the Batman. When The Joker barged in on a meeting between the city's mob leaders, Gambol developed an immediate hatred of the clown. Since the Joker had stolen from Gambol and the other mob leaders and started insulting Gambol after crashing the meeting, an enraged Gambol put a sizeable bounty on the psychopath's head.
Later on, Gambol is greeted by a group of thugs claiming to have killed the Joker, bringing the clown's body wrapped in bin bags as proof. However, these thugs are actually working for the Joker, who is still alive and grabs Gambol, putting a knife to his face. The Joker goes on to tell Gambol the story of how he got his facial scars (which may or may not be true) and then slices Gambol's mouth. The moment of slicing isn't shown on-screen, only one of Gambol's goons wincing in disgust at the moment the Joker kills the mob boss.