Polymos

Polymos was the home planet of the Nestene Consciousness.

The Nestene completely infused the planet, destroying any other life on it. It was far from a red star and had surprisingly little tectonic activity. Far in the future, it was invaded by the Time Lords, attempting to stop the plastic asteroids from leaving. (PDA: Synthespians™)

Polymos was one of the many Nestene protein planets destroyed in the Last Great Time War. (DW: Rose) The Darksmith Collective salvaged plastics from its wreckage in the 28th century in order to build the robot called the Agent. (TDL: The Dust of Ages)

It was located at the edge of the Mutter's Spiral galaxy. (DWN: Doctor Who and the Terror of the Autons)