In 1954, he had a regular role playing "Bavarro" in the children's science-fiction TV series "Rocky Jones, Space Ranger". Two years later, he played a train conductor in the episode "Safe Conduct" of "Alfred Hitchcock Presents", appearing with future co-star Werner Klemperer (Colonel Klink in "Hogan's Heroes"), who played a spy. He also played Nazi villains in several later films: the German town mayor in "The Young Lions" (1958); Rudolf Höss in "Operation Eichmann" (1961); and Gregor Strasser in "Hitler" (1962). The year before the premiere of "Hogan's Heroes", Banner portrayed a World War II German "home guard" soldier in "36 Hours" (1964), starring James Garner. Although it was a serious role in a war drama, Banner still displayed some of the affable nature that became his defining character trait the following year in "Hogan's Heroes". By coincidence, during the final moments of "36 Hours", John Banner's character meets up with a border guard played by Sig Ruman, who had portrayed another prisoner-of-war camp chief guard named Sergeant Schulz in the 1953 film "Stalag 17", starring William Holden.