Fontaine's family immigrated from Italy to MegaKat City when he was a child. Fontaine's father ran a garage and insisted that his son speak only Italian and would beat him anytime he spoke English. There is not much known about Fontaine's childhood before he became a criminal, however he have always dreamed of becoming one. Fontaine one day stabbed his childhood bully and his girlfriend to death which impressed Mac and Molly Mange, who saw the whole thing while they were outside arguing. Fontaine started to raise through the ranks in the Mange mafia due to his thirst for violence. In his final test, Fontaine confronted his father in his garage (Mac and Molly were the only ones who knew about their relationship) and told his father that he doesn't truly hate him, he just him this way before beating him horribly with his brass knuckles. Fontaine soon left the Mange Mafia after Mayor Manx denied Mac and Molly's paroles and since he didn't feel comfortable with Katscratch being in charge. Fontaine was then hired to work for Dark Kat who gave him a book called 'The Bible of Evil' which always made Fontaine claim to be reborn thanks him and he became a complete sociopath. Fontaine recruited corrupt politicians, captains of industry, and those with leadership ranks in the Enforcers into his evil cult. Fontaine even felt threatened by Feral which was why he put his money in developing a militarized criminal organization. Fontaine kidnapped Governor Lyons' daughter MBI Agent Nadine Lyons to sacrifice her in a ritual. Fortunately, they were apprehended by General Montana and the Army with assistance from Agent Jerome Weston and the SWAT Kats. Fontaine ended up in a coma since Montana tricked him into attacking explosive canisters that were placed around the Chinese theater.
-He was inspired by Bruno Manheim, a gangster from Superman who uses a similar book to Fontaine called 'The Bible of Crime'. Fontaine's first name was inspired by Bruno's father who was an old gangster named Moxie Manheim and the original leader of the Intergang. Fontaine even has a militarized criminal gang just like the Intergang who has access to high tech.
-He was also inspired by the Spider-Man character Hammerhead since he murdered his own father in his youth and enjoys using brass knuckles as his weapons. Fontaine is highly skilled in the organization, concealment, and management of criminal enterprises. He is an effective hit-man, a skilled marksman (his preferred weapon was the Thompson submachine gun as well as brass knuckles), and an excellent street fighter.