The oyster crab is a small crustacean, with a body that resembles an oyster shell. It is also known by various other names, including oyster biter, oyster robbing crab, and oyster thief. Other synonyms for oyster crab include sponge crab, mud crab, and rock crab. These crabs are commonly found in the intertidal zones of saltwater estuaries and bays, where they feed on oyster larvae and other small organisms. While they may be a nuisance for oyster farmers, oyster crabs play an important role in the marine ecosystem and provide food for larger predators such as fish and birds.