Rhagorthua is a fictional deity created by David Conyers for the Delta Green setting of Chaosium's Call of Cthulhu role-playing game.
Background[]
Rhagorthua is a fiery Great Old One similar to Cthugha, who is able to absorb nuclear radiation. The entity is imprisoned somewhere within the subsoil of New Mexico, trapped in a death-like state before being awoken by the Trinity atomic blast of the Manhattan Project. Now partially freed, Rhagorthua sent out radioactive winds as a call for someone to fully free it. Despite still being trapped for nearly sixty years, Rhagorthua patiently waits for its freedom. (EXP: A Handful of Dust)