The Nestene was a hive-mind species and the only surviving lifeform on the planet Polymos.
The Nestene was a disembodied consciousness of immense power with the ability to incarnate itself or portions of itself inside plastic objects, appearing to give them life. Though it did not possess a fixed physical form, the Nestene was capable of building itself one, always of large size and eldritch appearance, which would boost its telepathic powers.
Individual animated mannequins of plastic created by the Nestene were known as Autons; while many were no more than puppets that belonged in full to the main consciousness, the Nestene was capable of splitting portions of its cognition and granting them to the Autons, who would maintain a psychic link with the rest of the Nestene but operate as fully-fledged individuals. The Nestene's control over Autons and other plastic puppets could be boosted with electronic transmitters.
The Nestenes used to be a species of octopoid aliens, the dominant sentient species of the planet Polymos, whose bodies were made of plastic-like material instead of organic components. At some point in their evolution, the Nestenes gained telepathic abilities to the point that their minds merged into a single consciousness, known henceforth as the Nestene.
Start of ConquestsEdit
Though now pure energy, the Nestene still needed organic fuel for nutrition, as well as new plastic to expand its physical forms, which it achieved by conquering planets. One of the planets it visited was Earth; though the planet would have been suitable for consumption, the Nestene foresaw that intelligent beings, clever enough to craft plastic, might evolve there in time, and so instead it left Earth untouched but buried a few frozen independent Nestene creatures in its soil, that they may conquer it in time, taking advantage of humanity's plastic creations, before calling the main Consciousness back to the planet.
Facing the DoctorEdit
In the second half of the 20th century, the Nestene, having detected that Earth was "ready", made an attempt to take it over. It sent several meteor-like beacons to the planet, which beamed part of its immaterial consciousness into nearby plastic items. Growing in power, the Nestene took over a mannequin factory, developing mannequins with hidden weapons, known henceforth as Autons; these operations were overseen by a splinter of the Nestene called Channing, a lifelike Auton who was granted independent will. However, in the Nestene's first encounter with him, this attempted invasion was thwarted by the Doctor (then in his third incarnation) alongside U.N.I.T..
A few years later, the Doctor's rival, the Master, gained control of a Nestene meteor and made a deal with the Nestene, using Autons and other plastic creations of the Nestene's to further his own ends, but the Doctor managed to convince his nemesis that partnering with such a powerful and amoral entity as the Nestene was a dangerous venture, and the two Time Lords cut off the meteor's connection to the wider Consciousness.
The Time War and AftermathEdit
The Nestene was an important enough entity in the universe that it found itself dragged into the Time War that erupted between the Daleks and the Time Lords. Though gaining time-travel technology in the course of the War, and fine-tuning its powers to the extent that it could remotely convert any plastic mannequin into a fully-equipped Auton, the Nestene lost all the planets it had conquered and used as reservoirs of protein in the War.