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 some territories, the film was marketed as "E.T. - The Second Coming."
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).
Originally filmed in French and Spanish, the actors learned both languages. It premiered in France before Spain.