The "crab gods", as the Ogrons called them, were inhabitants of the Planet. The Ogrons began to worship the crab gods when they ate the rock gods. (AUDIO: Planet of the Ogrons, Too Many Masters)
During the Last Great Time War, Doctor Ogron convinced the crab gods to help him fight the Daleks, allowing him to convince the other Ogrons to fight with him too. (AUDIO: Planet of the Ogrons)
Empress Maule of the Ogrons once tried to sacrifice Missy to a crab god. (AUDIO: Too Many Masters)