Sebastian’s body is shaped like a sea snake, it is elongated with blue scales. At the end of his body is a large tail fin. Sebastian’s skin is light blue. His torso is humanoid, with two larger arms and one smaller arm on his right side. Sebastian’s hands are humanoid, four fingers with claw-like ends. His face retains a humanoid face with fish-like features, like an anglerfish bulb on his forehead, fin-like appendages on his head, a fish like mouth and a third eye on the left side of his head.