Crabs

Crabs are decapod crustaceans which can be found living in oceans, in fresh water, or on land, generally covered with a thick exoskeleton and armed with a single pair of claws. True crabs typically have a very short projecting "tail" or have a reduced abdomen entirely hidden under the thorax. Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs and crab lice – but these are not true crabs.