 Robby is a mechanical servant that Morbius has designed, built, and programmed using knowledge gleaned from his study of the Krell, a long-extinct race of highly intelligent beings that once populated Altair IV.The film’s plot appears 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.