They may look like something from a 1950s sci-fi film, but Japanese spider crabs are gentle giants.

And giants they are. Of the 60,000 species of crustaceans on Earth, Japanese spider crabs are the largest, spanning up to 12.5 feet from the tip of one front claw to the other. They’re also one of the world’s largest arthropods, animals with no backbone, external skeletons, and multiple-jointed appendages. In this crab’s case, those appendages are its 10 legs.

Japanese spider crabs live on the Pacific side of Japan as far south as Taiwan and at chilly depths ranging from 164 feet to as low as 1,640 feet. (They spawn at the shallower end of that spectrum.) They thrive in temperatures of