The Zodiac Crustacean is the CRAB, which is a four-letter word. Crabs are a type of decapod crustacean, which are animals with ten legs and a hard exoskeleton. They are found in all of the world's oceans, as well as in freshwater and on land. Crabs are omnivorous, meaning they eat both plants and animals. They are known for their ability to walk sideways, and they use their claws to defend themselves and capture prey.