Robby the Robot is a fictional character and science fiction icon who first appeared in the 1956 film Forbidden Planet. He made a number of subsequent appearances in science fiction films and television programs, which has given him the distinction as "the hardest working robot in Hollywood". The name "Robbie" (spelled with an "ie") had appeared in science fiction before Forbidden Planet. In a pulp magazine adventure The Fantastic Island (1935), the name is used for a mechanical likeness of Doc Savage used to confuse foes. The name is also used in Isaac Asimov's short story "Robbie" (1940) about a first-generation robot designed to care for children. In Tom Swift on The Phantom Satellite (1956), it is also the name given to a small four-footed robot designed by Tom Swift Jr., the boy inventor in the Tom Swift Jr. science fiction novel series by Victor Appleton II. Robby the Robot originated as a supporting character in the 1956 MGM science fiction film Forbidden Planet. The film's storyline centers on a crew of Earth explorers who land their starship, the C57-D, on the planet Altair IV, inhabited by the mysterious human Dr. Morbius and his daughter Altaira who was born there. Robby is a mechanical servant that Morbius has designed, built, and programmed using knowledge gleaned from his study of the ancient Krell, a long-extinct race of highly intelligent beings that once populated Altair IV. The film’s plot is loosely based on William Shakespeare’s play The Tempest (1610), with the planet Altair IV standing in for Shakespeare’s remote island and Dr. Morbius for Prospero. In this context Robby is analogous to Ariel, a spirit enslaved by Prospero. Robby exhibits artificial intelligence, but has a distinct personality that at times exhibits a dry wit. He is instructed by Morbius to be helpful to the Earthmen and does so by synthesizing and transporting to their landing site 10 tons of "isotope 217", a lightweight though still effective replacement for the requested lead shielding needed to house the C57-D’s main stardrive to power an attempt to contact Earth base for further instructions.