Born in Queens, NY, Young began acting after serving in the Marines in the late 1950s, and working as a carpet salesman and amateur boxer. He accompanied a friend to an audition for famed acting coach Lee Strasberg, who instead accepting Young into the Actor's Studio. Strasberg soon became a close friend to the novice actor, who soon made his debut on stage off-Broadway productions. Young made his screen acting debut billed as John Harris in the low-budget horror picture "Carnival of Blood" (1970) for notorious adult film director Leonard Kirtman. Young's offbeat delivery, which turned from quirky and humorous to threatening or sympathetic at a moment's notice, quickly ushered him out of the grindhouse ghetto and into mainstream fare. He soon impressed audiences in supporting turns for such films as "The Gang That Couldn't Shoot Straight" (1971), "Across 110th Street" (1972), and "Cinderella Liberty" (1973), which marked the beginning of his long friendship with actor James Caan. In 1974, Roman Polanski cast him as the lovelorn Curly, who hires detective Jake Gittes (Jack Nicholson) to investigate his wife's infidelity in "Chinatown," while Sam Peckinpah tapped him to play a getaway driver opposite Caan and Robert Duvall in the violent thriller "The Killer Elite" (1975). Young also enjoyed guest appearances on several crime programs during the period, including "Baretta" (ABC, 1975-78), for which he would also pen his first teleplay.In 1976, struggling actor Sylvester Stallone cast Young to play meat plant worker Pauline Pennino, whose sister Adrian (Talia Shire) was the object of the pug boxer's affections, in "Rocky." Young provided the majority of comic relief for the underdog tale, which went on to become a box office and cultural phenomenon, while earning Young a 1977 Oscar nomination for Best Supporting Actor. The increase in profile from "Rocky" gave Young's acting career a strong boost, as he continued to essay supporting turns in films and television through the 1970s, including a reunion with Peckinpah for the disastrous "Convoy" (1978) and Robert Aldrich in "Twilight's Last Gleaming" (1977). He also showed his considerable talent as a writer with scripts for the TV-movie "Daddy, I Don't Like It Like This" (CBS, 1978), with Young and Shire as the heads of a family struggling with poverty, and the feature "Uncle Joe Shannon" (1978), about a jazz trumpeter (Young) and his daughter. The latter, largely based on Young's relationship with his daughter, actress Anne Moreau, was a critical and commercial flop, and unfortunately seemed to signal the end of Young's fledgling efforts as a screenwriter.Young was remarkably busy throughout the late 1970s and 1980s with appearances in big-budget Hollywood productions and a host of smaller, independent pictures with varying degrees of quality. He was naturally brought back for all three "Rocky" sequels in the ensuing decades - "Rocky II" (1979), "Rocky III" (1982), and the highly-successful, but completely soulless "Rocky IV" (1985). But Young also gave memorable performances in Sergio Leone's "Once Upon a Time in America" (1984), which he followed by playing psychotic mob boss Bed Bug Eddie in "The Pope of Greenwich Village" (1985) and Rodney Dangerfield's pal and chauffeur in "Back to School" (1986). Of course, Young participated in his share of misfires, playing an abusive dad who falls victim to his bedeviled son in "Amityville 2: The Possession" (1982) and appearing in the short-lived comedy "Roomies" (NBC, 1987), with Young as a former drill instructor who shares a college dorm room with a child prodigy (Corey Haim). Meanwhile, he returned to the stage in productions of "Rats" for Al Pacino and the blockbuster Broadway run of "Cuba and His Teddy Bear," opposite Robert De Niro and Ralph Macchio.Young settled into a comfortable routine of playing mobsters and gritty types for most of the 1990s, appearing to not mind being typecast at all. His light comic touch made the most of his appearances in the best of his later films, which included "Betsy's Wedding" (1990) and "Mickey Blue Eyes" (1999). A few directors remembered Young's versatility and cast him in more nuanced character parts, like "Bright Angel" and Nick Cassavetes' "She's So Lovely" (1997). But for the most part, Young was content to play Mafiosi in films and television productions like the popular "Vendetta: Secrets of a Mafia Bride" (Syndicated, 1991) and "Mario Puzo's The Last Don" (CBS, 1997). There was also a reprise of Paulie in "Rocky V" (1990), which proved to be about the only positive thing about the woeful sequel.Young busied himself in independent and international productions after the new millennium while enjoying critical accolades for his paintings, which were shown in galleries all over the world. There were also stage appearances in New York and Los Angeles, as well as a few standout film and television roles. He was the terminally ill father of Bobby Baccalieri (Steven R. Schrippa) on a 2001 episode of "The Sopranos," which concluded with the former top killer losing his own life after rubbing out his own much-detested godson. Young also displayed his comic and dramatic talents as the bewildered father of a transsexual (Felicity Huffman) in the indie "Transamerica" (2005). He later appeared as himself alongside Sylvester Stallone on the reality series "The Contender" (NBC-ESPN-Versus, 2005-), before picking up the mantle of Paulie for the sixth and apparently final "Rocky" film, the successful and redemptive "Rocky Balboa" (2006).