Part of Breaking Bad featuring Bryan Cranston, Aaron Paul, Anna Gunn, Dean Norris, and Betsy Brandt.
He trained under Stella Adler in the early 1960s, serving as her personal assistant for nearly three years to pay for classes, then spent the next twenty years doing Off-Broadway plays and running a coffee house on MacDougal Street in the Village. Scarface (1983) gave him Alberto "the Shadow," a cartel henchman with real screen time. He's said that six months after the film wrapped, he had to take a real estate job to pay the bills. Darren Aronofsky cast him in Pi in 1998 and kept casting him in everything that followed. Hector Salamanca was still a decade away.
The Emmy nomination in 2012 was for a role with no dialogue. His Hector Salamanca communicated entirely through facial contortions and a brass bell, and it was enough to land a Guest Actor nod for the Breaking Bad Season 4 finale where Salamanca detonates himself to take out Gus Fring. He came back for 22 episodes of Better Call Saul, playing a younger Salamanca who could still walk and talk. His final role was a Mafia patriarch in Your Honor Season 2, reuniting with Bryan Cranston months before his death. He joked he was "the second-most famous bell ringer after Quasimodo." At 83, that seemed like a fair trade.
The Salamanca performance came from his mother-in-law Shirley, who suffered a stroke and reportedly spent years in a nursing home. He borrowed her facial contortions directly. Despite spending his career playing Latino villains and Italian mobsters, he was Jewish, son of Polish and Russian Jewish immigrants. Darren Aronofsky cast him in all six of his first films, from Pi to Noah, starting when Aronofsky scraped together $100 contributions for a $60,000 debut. He called himself "just a journeyman actor" his whole career. The bell suggests otherwise.
Bryan Cranston posted on Instagram that Margolis was "a really good actor and a lovely human being" whose absence was "deeply felt." Bob Odenkirk wrote that Margolis "made me laugh in the van on the way to set." His son Morgan confirmed the death; the family held a private funeral and requested donations to the Juvenile Diabetes Research Foundation in lieu of flowers.