The Spidrons were an arachnid species. They had spider-like bodies, six legs, humanoid faces and claw-like hands. They shared their homeworld with primitive ape-like beings and dinosaur-like creatures.
The Spidron emperor was the only member of his race who possessed intelligence. The Spidrons preyed on the ape-like beings until they seemed to become extinct, then the emperor had them abduct primitive beings from other worlds. To protect themselves, he hid their solar system behind the illusion of a supernova.
The Third Doctor and Arnold followed a Spidron space fleet through the illusion in the TARDIS, landed on their homeworld and discovered their underground city. They were captured and taken to the emperor, who ordered their deaths. Escaping, the travellers encountered the surviving ape-like beings, and after defeating their chief in a duel, worked with them to attack and destroy the Spidrons. (COMIC: Nova)