Chris Phillips provides the voice for Marty Chonks.
Marty is married to Mrs. Chonks and runs the Bitch'n' Dog Food Factory in Trenton, Portland Island, Liberty City. He has grievances with many people, which he takes care of by killing them and turning them into dog food.
Marty Chonks eventually employs Claude to transport various people to his factory, and then destroy any evidence in the car. Victims include his bank manager, two burglars and his wife, Mrs. Chonks. Marty then sends Claude to get Carl, who had been having an affair with Mrs. Chonks, who Marty believes he can overpower. Carl brings a shotgun and kills Marty, saying that he's there to take over the business. Claude has the opportunity to kill Carl after the mission, and see Marty's dead body before it disappears.
The missions that Marty gives are a spoof of the 1989 film "The Cook, the Thief, His Wife & Her Lover". The missions are entitled The Crook (the bank manager), The Thieves (two burglars), The Wife (Mrs. Chonks) and Her Lover (Carl), although the movie ends with the wife killing her husband, as opposed to Marty killing his wife.
- Marty's accountant - Murdered for stealing a share of Marty's earnings.
- Two thieves - Murdered so they would not be able to inform the police that he had employed them to break in to his house.
- Mrs. Chonks - Murdered due to her lavish spending and infidelity.
- GTA III
- Marty Chonks is the only one of the pay phone mission bosses in GTA III who actually appears in the game physically, not voiced unlike El Burro, King Courtney and D-Ice.