They're not quite the humanoid killers seen in the Terminator films, but these unsettling machines have got the internet up in arms.
Scientists have created tiny machines that can eat, grow and even evolve just like real creatures, sparking fears of a robot uprising.
Eventually, they age and die, a level of lifelike complexity never before seen in robots.
The news has startled online commenters, with one comparing the work to 'Skynet' – the fictional evil corporation behind the Terminator robots.
According to Professor Dan Luo, a biologist at Cornell University who worked on the project, the machines are about as complex as a simple organism like mold.
"We are introducing a brand-new, lifelike material concept powered by its very own artificial metabolism," Professor Luo said.
"We are not making something that’s alive, but we are creating materials that are much more lifelike than have ever been seen before."
He and his team grew their robots using an artificial bio-material based on DNA.
The material has the properties of living things, including the ability to metabolize – generate and use up energy – and self assembly.
When left to its own devices, the material formed small machines that moved on their own, grew, evolved, consumed resources and eventually died.
Scientists even pitted them against one another in competitive races.
The machines are not alive themselves, but act like living things, and could pave the way for self-sustaining robots.
"Ultimately, the system may lead to lifelike self-reproducing machines," said team member Shogo Hamada.
he move may spark fears over autonomous robots taking over the planet by learning to reproduce and upgrade themselves.
Online commenters described the machines as "terrifying".
"Is Cornell trying to be the next Skynet? This is scary as f**k," one Twitter user wrote.
Another wrote: "Didn't anybody see any of the 'Terminator' movies? Are we just going to let this happen?? Really???"
"This is how humanity ends," one user quipped.
Billionaire Elon Musk has previously warned that such intelligent machines could become "an immortal dictator from which we can never escape".
His fears are echoed by Microsoft founder Bill Gates, who last month said the threat to humanity posed by AI is similar to that of nuclear weapons.
This story originally appeared in The Sun.