Reptilicus

Reptilicus is a 1961 Danish Kaiju movie, in the vein of Godzilla.

It is notable for being the first and only Danish Kaiju film.

Had a short lived adaptation from Gold Key Comics, but because they bought the film rights from the American distributor and not the Danish creators, they had to drop the title after issue 2. The story continued, however as Reptisaurus.

Tropes used in Reptilicus include:

Backed by the Pentagon: Featured dozens of soldiers and displays of some of the best gear possessed by the Danish army (unusual at the time; most similar movies had to rely on Stock Footage).
Healing Factor. Ridiculous amounts of it. Not quite as bad as Cell but close.
Hollywood Acid: The monster's main weapon, in the U.S. cut, aside from being a giant lizard of doom.
Psycho Electric Eel: Played for laughs.
Same Language Dub: The film was shot with the cast phonetically speaking their lines in English to make it easier to sell in America, but the cast's thick accents forced it's American distributors to re-dub the entire film.
Technicolor Science: That's a rather interesting laboratory in the Akvarium.
The End - or Is It?: Yay! The army made Reptilicus swallow a poison missile, and now it's dead! Denmark can now go back to normal life! Except that the piece of Reptilicus severed by a depth charge is now twitching...
You Fail Biology Forever