The film was originally intended as a low-budget horror movie about an evil alien. After the success of E.T. the Extra-Terrestrial (1982), the producers made the alien into a lovable character, and added a kid who befriends it. Director Juan Piquer Simón was not satisfied with the final result.
In the Film Ventures version, retitled, "Pod People" (as shown on Pod People (1991)), the scenes during the opening credits come from a completely unrelated film, The Galaxy Invader (1985).
In some territories, the film was marketed as "E.T. - The Second Coming."
Originally filmed in French and Spanish, the actors learned both languages. It premiered in France before Spain.