It Came from Beneath the Sea (1955)

It Came from Beneath the Sea (1955) begins when the U.S. Navy’s newest submarine encounters trouble on its first cruise. The trouble turns out to be a giant octopus that was disturbed by nuclear tests in the Pacific.

The Beast from 20,000 Fathoms

Nuclear tests in the Arctic thaw a dinosaur from the ice and it sets out for New York leaving a path of destruction in its wake.