From Wikipedia: “Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" . . . usually entirely hidden under the thorax. read more
Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs, and crab lice – are not true crabs.” Crab - Wikipedia “Scorpions Scorpions are predatory arachnids of the order Scorpiones. read more