The closest relatives of the crabs are anomurans , a crustacean group which includes animals such as hermit crabs , king crabs and squat lobsters . They look a lot like crabs and many have the word ` crab ' in their name , but are not true crabs . Many other animals with similar names â `` such as hermit crabs , king crabs , porcelain crabs , horseshoe crabs and crab lice â `` are not true crabs .