A few of the recurring enemies who face Doctor Who have joined the higher echelon of science fiction aliens. Most nerds, even those who don't care about the long-running British series, could draw a Dalek from memory. Other antagonists are crucial to the lore but less common in the series. Look at the Autons, who appeared in two Doctors' debuts with a multi-decade gap between them.
The 2005 reboot of Doctor Who underwent several stages of public reception. Many fans with fond memories of the original series were scared off by the first season. The 10th Doctor David Tennant's tenure brought in armies of new supporters who quickly became the show's dominant fanbase. By now, the franchise has earned a new level of widespread distaste. It's challenging to recall Christopher Eccleston and Billie Piper's first days.
What are the Autons?
The Autons are plastic machines that resemble mannequins. The early models are mute, awkward, and obvious. As invaders, they cannot blend in. Later iterations would be harder to spot. They have a hidden weapon in their wrists that can kill or stun targets. They're technically not robots, as they're not animated by internal electronics or any sort of mechanical wizardry. The Autons are the emissaries of a powerful alien hive mind. Various species across the galaxy know them by different names. They're called Autons on Earth because they originate from a company called Auto Plastics. Their creator is a hive mind called the Nestene Consciousness, which has a unique history in the franchise.
The Nestene Consciousness is one of the oldest alien races in the universe. They're one of a few species to exist in the "dark times" before the Time Lords brought rationality to the timeline. This period of chaos would have been impossible to live within easily. Anything that survived the eras before history would be horrific. The Nestene are worse than most would imagine. They were born as a singular being, thought to be a telepathic cephalopod. That organism is canonically the offspring of Shub-Niggurath, H. P. Lovecraft's Black Goat of the Woods with a Thousand Young. One of the Old God's spawn infused itself into an entire planet, creating the Nestene Consciousness. Rassilon of the Time Lords trapped and annihilated most of the Nestene, forever reducing them to a tiny fraction of their power. The Nestene Consciousness remained a threat for the rest of time, invading planets across space.
The Autons in the original Doctor Who
The Autons' first appearance came in a 1970 episode entitled "Spearhead from Space." It was the first episode of the series filmed in color. It was the debut of the Third Doctor, Jon Pertwee. Autons appear as clothes shop mannequins who come to life and attack. The Nestene Consciousness hides in a toy factory, planning to build accurate replicas of politicians and government figures to take over the world. The Doctor finds his TARDIS disabled by the Time Lords, trapping him on Earth. He meets his new companion, Dr. Liz Shaw, and his old ally, UNIT Brigadier Lethbridge-Stewart. The Doctor and Liz find the central hub of the Nestene Consciousness and shut it down with an electroshock device. The Autons deactivate, and The Doctor reluctantly joins UNIT. The Autons would appear again the following year. They're an evil army in the episode that introduces the Master, "Terror of the Autons." They were meant to appear in a 1986 episode, but they were left out, resulting in a 34-year gap for the Autons.
The Autons in the new Doctor Who
The grand return of Doctor Who selected the Nestene Consciousness and the Autons as its primary villain. "Rose" introduces the titular Rose Tyler, a teenage department store employee attacked by the surrounding mannequins. The Doctor destroys her workplace and then visits her home to enlist her help. An Auton replaces Rose's boyfriend, but the Doctor saves her from his attack. They are both kidnapped and dragged to meet the Nestene Consciousness again. Rose drops a vial of anti-plastic solution into London's water supply, destroying the Nestene Consciousness and deactivating the Autons again. The Doctor takes Rose home and then convinces her to join him as his new companion.
The Autons are a fun example of a simple concept being regularly built upon until it's absurdly massive. Their first appearance imagined the Nestene Consciousness as a tentacle monster in a toy factory sending mannequins out to attack Londoners. It was almost certainly created to make an episode about the dummies sitting in clothes shop windows coming to life. A few decades later, the Nestene became the unholy spawn of one of Lovecraft's Old Gods with all the cosmic horror that entails. Doctor Who loves to create silly concepts and gradually shift them into impossible nightmares. The Autons are simple, but they're part of a galaxy-spanning conspiracy that could have been the end of all things.