A is for... Autons

Creatures of plastic created by the Nestene Consciousness. As the Nestene is formless, the Autons provide a workforce for it, as well as a formidable weapon. The Autons were first encountered by the Doctor soon after he had regenerated and been exiled to Earth by the Time Lords. A small meteor shower had brought the Nestene to Earth - in the form of spherical energy units. These could take over the mind of susceptible humans. An Auton replica was created, of a man named Channing. He took over a small plastics company close to the landing site, dominating the will of its owner George Hibbert. Six months later, a larger shower of energy units landed in the same vicinity. These were collected by other Autons - basic models with crude, unfinished features. They were armed with weaponry built into their right hands. These could kill, and a command of "total destruction" could completely vapourise a body. Channing prepared a tank in which the Nestene could create a form for itself. Its shape would depend on the local environment, and even Channing had no idea what it would look like.

As well as the crude functionaries, Channing also created an army of Autons that would be shipped out as shop window mannequins across the country. A number of high ranking civil servants were abducted and replaced with identical Auton replicas. These were concealed as exhibits in Madam Tussaud's waxworks until needed. When the Nestene form was ready, the shop window dummies would be activated - programmed to kill and destroy. The replicas would ensure chaos amongst the armed forces and emergency services, ensuring Nestene victory. The Doctor devised a weapon that could destroy the fraction of Nestene Consciousness which animated each Auton. It transmitted a UHF signal. This was used to eliminate the replica of regular army General Scobie, which had been working against UNIT. The device also proved effective against the Nestene, which had taken the form of a huge tentacled creature. When this died, all of the Autons collapsed, lifeless plastic once more.

One of the energy units survived. The Brigadier allowed it to be loaned out for an exhibition, and it was stolen by the Master. He planned to bring the Nestene back to Earth. He first took control of a plastics factory, and created a new squad of Auton functionaries. Still featureless, they had smoother faces, and had the ability to speak. They were costumed as policemen in order to abduct the Doctor, and later in grinning carnival masks and bright yellow blazers to distribute plastic daffodils.

These flowers could eject a smothering plastic film over their victims' faces - triggered by a signal from a radio telescope. This would be the site of the Nestene's materialisation. The Doctor succeeded in convincing the Master that he would never be spared by the Nestene, and so the two Time Lords collaborated to eject the Consciousness back into space. This caused the Autons to collapse.

After its colony worlds were wiped out in the Time War, the Nestene Consciousness once again turned its attention to Earth. The Doctor informed Rose Tyler that this was due to its high levels of chemical waste, on which the Nestene thrived. Shop window mannequins were once again employed to act as the invasion force - animated by a control signal generated from a base beneath the London Eye. An Auton replica of Rose's boyfriend, Mickey Smith, was created as part of a plot to ensnare the Doctor. The real Mickey was abducted and kept alive - much as General Scobie had been in the earlier invasion attempt. The Doctor tried to convince the Nestene to leave the Earth alone, but he had in reserve a phial of anti-plastic. This destroyed the Nestene form, so that the Autons returned to inanimate plastic. This invasion attempt was one of the incidents witnessed by Elton Pope, who had met the Doctor as a child.

When the Doctor visited the area near Stonehenge in 102 AD, he found himself facing a gathering of many of his alien enemies. He enlisted soldiers from a nearby Roman camp to help fight against them. They were led by a Centurion, who just happened to be companion Amy's resurrected fiance - Rory Williams. This wasn't the real Rory, however, but an Auton replica with all of his memories. The Nestene had joined the alliance against the Doctor, which planned to imprison him forever in the Pandorica - to prevent him from destroying the universe. The Roman soldiers were all Autons.

As well as all of Rory's memories, his Auton replica also held his emotions and ideals. He joined the Doctor in a plan to save Amy, who he had been programmed to kill. She was placed in the Pandorica, and he looked after her for the next two millennia. It was believed that he had been destroyed during the London Blitz, but he was working as a guard in the museum where the Pandorica was housed in 2010 when Amy was herself resurrected. The Doctor reset the universe with a second Big Bang. The human Rory still retained memories from when he had been the Auton duplicate.

Appearances: Spearhead From Space (1970), Terror of the Autons (1971), Rose (2005), Love & Monsters (2006), The Pandorica Opens / The Big Bang (2010).

• There has been some contradictory dialogue about the nature of the Autons over the years. It is claimed that the Nestene can animate any and all plastic, yet the shop window mannequins and the Autons created by the Master appear to have been made with a special formula of plastic - suggesting that utilising existing display dummies would not be sufficient. Presumably only the specially manufactured Autons would have the built-in guns.