"Zotz" is an ancient Mayan word that means "bat" (the flying mammal). In Mayan mythology there is a bat god called Camazotz.
The film was based on a novel written by Walter Karig. However, the novel was a satire on mankind and its destructive tendencies, while the film is a simple fantasy tale.
Zotz is an existing surname used by people. Walter Karig met one of those people and thought his name was exotic enough to use as a magic word.
After a series of a half-dozen highly successful horror features, usually with an exploitable gimmick, producer/director William Castle turned to comedy/fantasy for this film.
William Castle retained Ray Russell to write the screenplay. Russell had written the screenplay from his own story for Castle's previous film, "Mr. Sardonicus" (1961).
Louis Nye: as the death ray inventor. He and Tom Poston, along with Don Knotts, were regulars on The New Steve Allen Show (1961) and were famous for the recurring "Man on the Street" skits.
William Castle: [gimmick] Upon its initial theatrical release, "Zotz" plastic coins were given to ticket buyers.