He began performing as a voice actor in films in the 1930s. He was the voice of Cheetah in Tarzan films and produced the bird sounds in Disney's Snow White and the Seven Dwarfs (1937). Pullen's vocal contributions appear in many cartoons featuring Mickey Mouse, Betty Boop, and Popeye. Pullen was also the voice of the howling coyote in Cecil B. DeMille's "The Crusaders", and the squawks and jungle sounds for Martin Denny's "Quiet Village".