Class Ophiuroidea is a group of echinoderms commonly known as brittle stars. These marine creatures are characterized by their long, flexible arms that are easily broken off as a defense mechanism. Synonyms for this class include Ophiurida, Ophiuridea, and serpent stars. Ophiurida is derived from the Greek word "ophioura" which means "snake-tail", referring to their snake-like appearance. Meanwhile, Ophiuridea simply means "brittle stars". Serpent stars, on the other hand, are named after the resemblance of their arms to snake tails. Despite the different names, they all refer to the same group of fascinating marine animals that can be found in oceans all over the world.