"Klaatu barada nikto" is a phrase that originated in the 1951 science fiction film The Day the Earth Stood Still. The humanoid alien protagonist of the film, Klaatu (Michael Rennie), instructs Helen Benson (Patricia Neal) that if any harm befalls him, she must say the phrase to the robot Gort (Lockard Martin). The Robot Hall of Fame describes the phrase as "one of the most famous commands in science fiction" and Frederick S. Clarke of Cinefantastique called it "the most famous phrase ever spoken

This Wacky Bruce Campbell Line Ties ‘Army of Darkness’ to a Classic ’50s Sci-Fi