Robot (Lost in Space) arms. 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. Initially, the bellows-covered legs were articulated, and were
Robby the Robot by production designer Arnold "Buddy" Gillespie, art director Arthur Lonergan, and writer Irving Block. These concepts were refined by production illustrator Mentor Huebner and perfected by MGM staff production draughtsman and mechanical designer Robert Kinoshita. The robot's groundbreaking design and dazzling finish represented a radical advance on the conventional "walking oil-can" depictions of robots in earlier features and film serials, and the only previous film robot of comparable style and quality was the "Menschmaschine" created for Fritz Lang's "Metropolis" (1927). However, this did not come cheap: As with every aspect of the production of "Forbidden Planet", MGM spared no expense