Reptilicus

Reptilicus is the titular antagonist in the 1961 giant monster film of the same name. He is a giant dragon-like creature with the ability to regenerate from a single body-part.

Biography
Miners dug up Reptilicus's tail when they were drilling in Lapland. It is flown to the Danish aquariam in Copenhagen, where it is put in a cold room for study. Due to careless mishandling, the door is left open and the section begins to thaw, only for scientists to find that it is beginning to regenerate.

The creature is dubbed "Reptilicus" and it's regenerating ability is compared to other animals like earthworms and starfish. Once fully regenerated, it goes on a rampage across the Danish countryside to the panic-stricken streets of Copenhagen.

It is presumably killed when poisoned by ingenious scientists and military officers, and it's foot sinks to the bottom of the sea, leaving the film open-ended, as the foot could possibly regenerate.

Trivia

 * Reptilicus is the only Danish monster.
 * The special effects used to bring Reptilicus to life was a wired marionette.
 * The film was produced by both the American International Pictures and Saga Studios.
 * There was a deleted scene were Reptilicus flyed. It was cut because it was too unrealistic.
 * Reptilicus can spit neon green acid, albiet clumsily and randomly.