They are green and have sharp razor-blade crab-like arms with tentacles on the palms of their hands, and crab-like legs.g They have yellow luminescent eyes. There are several ethnicites. One ethnicity has and a cone-type head, and the other has a crocodile-type head. If two cremtons of two different ethnicities have a child, the child's ethnicity will be randomised between the two.
After the Holocaust, the Cremtons adapted and evolved to their harsh post-nuclear environment, and became far more naturally stronger.