King Crab Fact:
King crabs are a family of crab-like decapod crustaceans chiefly found in cold seas. Their large size means that many species are widely caught and sold as food. King crabs are generally believed to be derived from hermit crab ancestors, which may explain the asymmetry still found in the adult forms. Although some doubt still exists about this theory, king crabs are the most widely-quoted example of carcinization among the Decapoda.
Source: King Crab Facts