Reptilicus (1961)

Starring Bent Mejding, Asbjorn Andersen, Povl Woldike, Ann Smyrner, Mimi Heinrich
Directed by Sidney Pink
(actor & director credits courtesy IMDB.com)

A drilling operation discovers the fossilized tail of an ancient reptile, and on turning it over to scientists, they are able to regenerate the entire beast, which escapes and menaces the city.

Denmark produces its own version of Godzilla, and the results, considering the filmmakers' limited resources, aren't too bad, although the special effects don't hold up too well today.  The creature resembles a giant sea serpent with a snake like mouth that spits out acidic bile, and appears to be a puppet or manipulated by wires, rather than animated.  The filmmakers make an interesting choice in shooting the creature on a much grainier film stock than that used for the principal actors' scenes, unless this was necessary for the special effects, definitely giving the footage a unique look.  The story (by Pink and Ib Melchior) is fairly solid, following the blueprint of previous sci-fi pictures in the discovery of the beast, and the hunt for it by the military, featuring Carl Ottosen as the authoritative general in charge, who would later appear in Pink's Journey To The Seventh Planet.  Wikipedia notes that two versions actually were made, a Danish version directed by Poul Bang, and an English-language version helmed by Pink, which would be interesting to compare and contrast.  The picture overall is far from an exemplary monster movie, but it's more than watchable, and a horrifying sequence where an official raises a bridge while masses are fleeing across it, leading bicyclists to plunge into the ocean below has stayed with me ever since my first viewing.