Planet (Master of Spiders)

An Earth-like planet was home to a swamp inhabited by giant spiders and their ruler, the Master of Spiders. The Second Doctor arrived on the planet to test his newly invented ray gun, but were pursued by the Master and attacked by the giant spiders. The Doctor used both his recorder and his ray gun to escape from the spiders and destroy the Master's mechanical spider, after which he sealed the real spiders in their cave. (COMIC: Master of Spiders)