<P> The Class B - 9 - M - 3 General Utility Non-Theorizing Environmental Control Robot, known simply as Robot, is a fictional character in the television series Lost in Space . His full designation was only occasionally mentioned on the show . </P> <P> Although a machine endowed with superhuman strength and futuristic weaponry, he often displayed human characteristics, such as laughter, sadness, and mockery, as well as singing and playing the guitar . With his major role often being to protect the youngest member of the crew, the Robot's catchphrases were "It does not compute" and "Danger, Will Robinson!", accompanied by flailing his arms . </P> <P> The Robot was performed by Bob May in a prop costume built by Bob Stewart . The voice was primarily dubbed by Dick Tufeld, who was also the series' narrator, and Jorge Arvizu for the Spanish dubbing . The Robot was designed by Robert Kinoshita, who also designed Forbidden Planet's Robby the Robot . Robby appears in Lost in Space episode #20 "War of the Robots" and in episode #60 "Condemned of Space". The Robot did not appear in the unaired pilot episode, but was added to the series once it had been greenlit . </P> <P> Initially, the bellows - covered legs were articulated, and were moved separately by the actor inside . However, the metal edges inside the suit cut actor Bob May's legs, so changes were made . The legs were bolted together, and the robot was pulled along by a wire instead of walking as it had done before . A new lower section was constructed with the legs cut off at the knee . This was filmed either in close - up or behind something to obscure the actor's feet protruding out the bottom; this version of the suit was informally referred to by the cast and crew as "the Bermuda shorts ." </P>

Who built the robot in lost in space