My mum was not much for horror movies (like, AT ALL) so why she chose to take us little kids in the 60’s to see this movie … totally beyond me. Dad wasn’t there, we got our snacks in the lobby and descended into the dark belly of the theater with Mum to watch in stunned amazement as a male prisoner was dragged to the depths of some kind of steel ship. Once in the ship’s “dungeon”, the doors covering a huge monster are pulled back, revealing this massive, squirming, writhing green monster with lot of slimy, tentacle-like body parts and very memorable BRIGHT RED claws at the end of its appendages. It might also have had a bright red beak, but I’m not sure of that. The prisoner is tossed into the pit where the green monster with red claws hungrily awaits, and we watch as the prisoner / victim is swollowed up by this monster (not too graphic, as I recall, but super creepy to a little kiddo. Mom promptly got us up and out of the theater with a quick, confusing explanation and we never talked of it again.

Big green monster, lots of tentacles/appendages, slimy, red claws …

Any clues?