Hey Kelly, there's actually a difference between what you're seeing in the picture and a serpent star IMO. Serpent stars are smoother and have protrusions on the sides of their arms, or none at all. They tend to be more predatory, and will go after fish and other inhabitants. The starfish above is a brittle star, which is not nearly as aggressive, and will not reach out and grab a fish. They are similar in body structure and habits, but not in aggression as far as I'm concerned. Not a scientific opinion, just what I've picked up through the years.