Ghost crabs, also called sand crabs, are crabs of the genus Ocypode, common shore crabs in many countries. Characteristics of the genus include one claw being larger than the other, but this difference is not as marked as in male fiddler crabs.
Crabs are decapodcrustaceans living in any of the world's oceans, in fresh water, or on land, generally covered with a thick exoskeleton and armed with a single pair of claws. True crabs belong to the infraorder Brachyura, which typically have a very short projecting "tail" (Greek: βραχύς / brachys = short, οὐρά / οura = tail), or where the reduced abdomen is entirely hidden under the thorax. Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs and crab lice – are not true crabs.