Perhaps the most unusual "guest star" in the entire "Columbo" series is the robot who is programmed to provide Marshall Cahill with his alibi. "Robby" is best known for having starred in the Sci-Fi classic Forbidden Planet (1956) directed by Fred M. Wilcox, as well as in "The Twilight Zone" and, more notably, in the cult television series "Lost in Space" (1965).