"The Giant Behemoth" - 1959

Marine atomic tests cause changes in the ocean's ecosystem resulting in dangerous blobs of radiation and the resurrection of a dormant dinosaur that threatens London.

The Giant Behemoth is a 1959 monster film directed by Eugène Lourié, with special effects by Willis H. O'Brien, Pete Peterson, Irving Block, Jack Rabin, and Louis de Witt. The film stars Gene Evans and André Morell.