Reptilicus, a giant monster film about a prehistoric reptile, is a Danish-American co-production, produced by American International Pictures and Saga Studio, and is—upon close examination—two distinctly different films helmed by two different directors.
The original version, which was shot in Danish, was directed by Danish director Poul Bang and released in Denmark on February 25, 1961.
The American version, which was in English with a nearly identical cast, was directed by the film's American producer-director Sidney W. Pink; this version was initially deemed virtually unreleasable by American International Pictures and had to be extensively reworked by the film's Danish-American screenwriter, Ib Melchior, before being finally released in America in 1962. Pink was angry at the changes and wound up in a legal dispute with AIP. After Pink and others viewed the English-language version, the lawsuit was dropped.
Danish miners Svend Viltorft dig up a section of a giant reptile's tail from the frozen grounds in Lapland, where they are drilling. The section is flown to the Danish Aquarium in Copenhagen, where it is preserved in a cold room for scientific study. But due to careless mishandling, the room is left open and the section begins to thaw, only for scientists to find that it is starting to regenerate.
Professor Otto Martens, who is in charge of the Aquarium, dubs the reptilian species "Reptilicus" (upon a reporter's suggestion) and compares its regeneration abilities to that of other animals like earthworms and starfish.
Once fully regenerated from the tail section, Reptilicus goes on an unstoppable rampage from the Danish countryside to the panic-stricken streets of Copenhagen (including one of its famous landmarks, Langebro Bridge), before finally being killed with poison by ingenious scientists and military officers.
However, the monster's foot is not destroyed and sinks to the bottom of the sea. The movie is left open-ended, with the possibility that the foot could regenerate.
- Carl Ottosen as General Mark Grayson
- Ann Smyrner as Lise Martens
- Mimi Heinrich as Karen Martens
- Asbjørn Andersen as Professor Otto Martens
- Bodil Miller as Connie Miller (Danish version)
- Marla Behrens as Connie Miller (American version)
- Bent Mejding as Svend Viltorft
- Povl Wøldike as Dr. Peter Dalby
- Dirch Passer as Peterson
- Ole Wisborg as Captain Brandt