Polymos was the planet in the Doctor Who TV series. It became the birthplace of the Nestene Consciousness when Shub-Niggurath came into the universe from the pre-universe and gave birth on the planet. As the Nestene lived on Polymos, it infused itself with the planet until all life on Polymos was killed and eaten by the Nestene.
The Nestene Consciousness remained on Polymos until it begain to send out plastic asteroids that would take over new worlds and infuse with them as well. As with other worlds, Polymos was used as a protein planet for the Nestene. However, during the Last Great Time War, the Time Lords invaded Polymos in an attempt to stop the plastic asteroids being sent out by the Nestene. It was in this conflict that Polymos was destroyed.