Ed Nelson "played" the crab monster with Beach Dickerson operating the monster's claws.

A scene involving two pilots was shot, but cut from the final finished film.

Allied Artists Pictures released this film on a double bill with Not of This Earth to many drive-in theaters with the tag line "Terrorama! Double Horror Sensation!"

Russell Johnson broke his toe while splashing around in the water during one scene. Due to the low budget of the film, director Roger Corman had a stage tech tape up Johnson's toe and immediately ordered him back in the water to finish the scene.