Johnny "Two-Dicks" Peralta is the Racket Boss of the gambling racket in Southdowns, running everything out of Wilcock's Saloon. A former leg-breaking enforcer turned bookie, the joke around Southdowns is that Johnny must have two dicks, because if you owe him, he's never gonna stop screwing you.
Everything from cards, a sports book, to shooting craps, if there's action in it, Tommy Marcano has Peralta running it. They have aspects of their gambling racket tucked into every nook and cranny of Southdowns, from dice games in back alleys to makeshift casinos in abandoned warehouses.
They even run illegal fights, where winners are recruited for bouts in The Acadia gym. Peralta's big money comes from fixing these fights by paying off or intimidating the favored fighters to throw the match, earning Peralta and Tommy a pile of cash.
In 1968, Peralta's racket was taken over by Lincoln Clay, who was working with inside information he received from Danny Little. Lincoln damaged Two-Dicks' gambling operations by killing his enforcers and other personnel, and damaging the racket's assets. Once everything fell apart, Peralta was drawn out, giving Lincoln the opportunity to confront him. After successfully infiltrating Wilcock's Saloon, Lincoln dealt with Peralta and ended his association with the Marcano Crime Family.