Greer made his film debut as an extra in the 1938 film "Jesse James", which was filmed mainly around Pineville, Missouri. He told the "Neosho Daily News" in 2002, "They were paying $5 a day – a day! – to local people for being extras. That was really good money in those days, more money than we had seen in a long time." Greer appeared in three episodes of "Adventures of Superman", including the inaugural entry, "Superman on Earth" (1952), in which he was cast as the first person ever to be saved by Superman. He was the major guest star, as a man framed for murder in "Five Minutes to Doom" (1954), and as an eccentric millionaire in "The Superman Silver Mine" (1958).