Gastrulans were sentient gastropods that stood slightly taller than a Sullustan of average height—around 1.5 meters—and possessed four short arms attached to their torsos that ended in paddle like hands with opposable thumbs. Their heads were bulbous, with a thin mouth that stretched across their faces and slightly down their necks. Gastrulans had dark spots across the back and front of their heads, as well as down the backs of their necks. While they had no visible nose or ears, they did have eyestalks that protruded from the sides of their head, near to where it joined their necks.