Robby the Robot is a 6-foot, 11-inch tall mechanical suit designed for an actor to wear, to play the part of a robot. It was originally designed for the 1956 MGM movie Forbidden Planet, and quickly became an icon.
As Forbidden Planet was inspired by Shakespeare's play The Tempest, Robby's character was inspired by Ariel, the sprite in the play. The first known use of the name "Robbie the Robot" was in the Doc Savage adventure, The Fantastic Island (published in 1935), as a nickname for a mechanical likeness of Doc, used to confuse foes. It is unknown if Robby the Robot was named in honor of this Pulp Era automaton or a later Asimov robot character likewise named (and perhaps also derived from the first Doc Savage usage).
An important feature of Robby was the command that he was not to inflict fatal harm upon human beings. This comes into play near the end of the film, where Robby is commanded to kill the monster, but cannot do so because it comprehends that the monster is an alter ego or extension of Dr. Morbius. Both the injunction against harming humans (the First Law of Robotics) and the name "Robby", were adapted from a story by Isaac Asimov from the science fiction story collection I, Robot. Although I, Robot was issued in 1950, the short story "Robbie" was published in 1940. Asimov's Robbie was a first-generation robot designed to care for children.
The "Robby" robot suit in Forbidden Planet was later reused in a less popular movie called The Invisible Boy. It made several further appearances in other movies and TV shows over the next few decades. While Robby's appearance was generally consistent, there were notable exceptions, such as the 1962 Twilight Zone episode "Uncle Simon", where he was given a somewhat more human "face". At other times, Robby usually retained the working gears inside his bubble head, although the details of his "brain" and chest panel were sometimes altered. Robby has made few television or film appearances since the 1970s, although he is featured in a 2006 commercial for AT&T.