Calvert worked as a bartender at the famed Sunset Boulevard nightclub, Ciro's, taking his professional last name from the brand name of Calvert whiskey. His real last name was Stevens. Calvert was the stand-in for actor Robert Lowery. Lowery helped get Calvert into the Screen Actors Guild. In 1948, Calvert bought the ape suits belonging to stuntman 'Ray "Crash" Corrigan'. Calvert's first job was playing the gorilla in the first Jungle Jim movie with Johnny Weissmuller.Calvert rarely asked for screen credit, preferring audiences to assume the "gorilla" was not human. He frequently made TV and live appearances in comedy sketches, including playing opposite Buster Keaton, Bob Hope, and Jack Benny.