The Marshmen

The Marshmen were mid-way on the evolutionary cycle between spiders and humans. They were the ancestors of the Alzarians (Adric was an Alzarian) aboard the Starliner. Rising at Mistfall from Alzarian swamps, they went straight for the Starliner, decapitating K9 on their way.

The Starliner was a home for the Alzarians for generations. The Starliner was grounded and the Alzarians were always replacing perfectly working equipment, and they thought that they would repair their ship and go home to their planet Terradon. Only the Chief Decider knew the truth, that on arrival, the Marshmen had massacred the original Terradonian crew. Having been instructed on the flight procedure by the Doctor, the Starliner finally took off with all of the Alzarians on the ship in search of their new home.

The Alzarians did not know that their ancestors were spiders until the Doctor told them. They thought that they were the descendants of the original crew of the Starliner, the Terradons.

The Marshmen were only in Full Circle