legged lizard that attacks Jack Driscoll was actually meant  to be an aetosaur, a reptile from the Triassic Period. However,  because of the high price of armatures (the metal skeletons for the  puppets), RKO cut costs by not having hind legs made for it. As a  result, the aetosaur has two forearms, no hind legs and a snakelike  appearance.