Antonio is the don of the New York Mafia, and one of several crime bosses who appear during the City Fall arc. He sent his henchman Marcello to fetch the Savate leader Victor to a meeting with several other criminal leaders, where he diplomatically broached the turf war that was starting between the Foot and the Savate. He was shocked when Victor brutally killed Marcello for disrespect.
Antonio was one of the bosses present during the Shredder's live execution of Victor, and obeyed Shredder's command to attack Splinter and the Turtles. After the battle, he presented Shredder with a tribute, and was rewarded with the assurance of a mutually beneficial arrangement.