During the 1960s and early 1970s, Kopell appeared in many television series, often sitcoms, including "Ripcord", "That Girl", "The Jack Benny Program", "Our Man Higgins", "Green Acres, Ben Casey," "The Flying Nun", "Needles And Pins", "McHale's Navy", "Lancelot Link-Secret Chimp", "Petticoat Junction", "The Streets of San Francisco", "Room 222", "The Mary Tyler Moore Show", "Bewitched", and "Kojak".