Mechanical Abomination

The Mechanical Abomination is a a robot, cyborg, computer, software entity or other manufactured being which has surpassed simple Artificial Intelligence and become an Eldritch Abomination in its own right. At the lower end of the scale, it is little more than a powerful monster, superhuman -- often dramatically so -- but still ultimately vulnerable to the "insignificant" humans who might oppose it.

However, most such creatures are usually beyond simply being "better" or "smarter" than humans -- they are for all practical purposes godlike in power, and said purposes are thoroughly and unambiguously malign -- at least as far as humanity is concerned. This may be a case of turning on its creators, or the inevitable result of an alien being's Blue and Orange Morality -- but either way, humankind is going to get the short end of the stick.

A Mechanical Abomination may not have explicitly supernatural powers, but when they do, they frequently start at Reality Warper and move on up the scale. However, even without mystic might, a Mechanical Abomination can still have fearsome power and reach -- consider what Colossus and Skynet were capable of.

Can be a sub-trope of Our Demons Are Different. Contrast Robotic Angel.

Anime and Manga

 * The Big Gete Star from Dragon Ball Z: The Return of Cooler started off as a mere microchip, but has grown into a nightmarish planet-sized hunk of metal and circuitry that can latch onto planets and completely devour them like a grotesque cancer cell. It comes into conflict with Goku and Vegeta when it absorbs the remains of Cooler, and is promptly taken over by the alien warlord when he becomes its new core and decides to go on a planet-killing spree For the Evulz. This leads to Cooler himself qualifying: as the Big Gete Star's Meta-Cooler Core, he's a twisted mechanical mockery of his original form, and only a sliver of his organic body remains in the form of a single eye and part of his face.
 * The Sibyl System from Psycho-Pass at its core is . It can read emotions and brainwaves, and will destroy lives at a whim if the person being read is pegged as a latent criminal, no matter if they're genuinely evil or not..

Comic Books

 * The Archie-published Sonic comics turn the reputation of the Tails Doll (mentioned in Video Games below) into an Ascended Meme. Its antenna is a disruptor gem that can hijack and subvert nanites; the doll can use this gem to destroy machines and even assimilate said nanites to take on a tentacled form with a vertical fang-filled moth, not unlike a shambling horror.

Fan Works

 * This Deltarune fanvid has the already-creepy turn into one of these upon taking Kris' SOUL. Taking a page from 's book,  is a massive techno-organic abomination seemingly made out of phone parts, computer parts, and an unsettling amount of human teeth, and his mere presence causes everything to glitch out uncontrollably.

Film

 * Colossus from Colossus: The Forbin Project "merely" controlled the world's nuclear arsenal. Once it started giving orders to the humans that built it, though...
 * Even more foreboding than Colossus is Skynet from the Terminator franchise. With both legions of skeletal Killer Robots and Time Travel at its metaphorical fingertips, it was as close to being a god as is possible without actual supernatural power.

Literature

 * AM from Harlan Ellison's classic story I Have No Mouth, and I Must Scream.
 * Obie from the later Well World books by Jack Chalker was forced to be this for a short time by a Restraining Bolt and a malign master.

Live-Action TV

 * Adam from Buffy the Vampire Slayer is this as a result of the experimentation to combine cybernetics and the supernatural.

Video Games

 * Okami gives us.
 * The Doom games have several types of these, including one simply named the Cyberdemon.
 * Kirby: Planet Robobot has several bosses that approach this level, partly as a result of Pop Star being mass-roboticized, including the Final Boss:
 * The subsequent phases of the boss fight reveal why.
 * The post-game side mode Meta Knightmare Returns and The True Arena reveal more about this mysterious entity:
 * The Tails Doll, one of the playable characters in Sonic R, has developed a reputation as this. Despite being created by Dr. Eggman and being described as a robot, it appears as an innocuous doll that displays no particularly mechanical traits, but possesses curious ability to levitate for long periods of time and even raising its arms in celebration should it win a race. Naturally, the Internet seized on the opportunity to turn the doll into the stuff of nightmares, which would turn into an Ascended Meme when the Archie Comics incarnation would go all-in with the cybernetic horror.
 * The Elder Scrolls is home to one of fiction's weirdest examples: the Numidium. Appearance-wise, it's a titanic brass robot created by the Dwemer, and has a recognizably humanoid appearance... but it's also capable of mind-breakingly eldritch feats. Powered by the heart of the universe's dead creator god, it can warp reality to crazy extents just by existing. And you don't have to look any further than its role in Daggerfall to see its power in action. This thing causes every separate, contradictory ending to be canon all at the same time in an event called the "Warp of the West", which forces entire landmasses, cultural mindsets, and political alignments to shift and transform without anyone even being aware of it. Even at its most mundane, it's the most powerful war machine in existence to the point that it allowed a pre-godhood Tiber Septim to conquer an entire kingdom in under an hour.
 * Tons of these are in The Legend of Zelda: Breath of the Wild, and they're all connected to the Sheikah. 10,000 years ago, they created all kinds of overwhelmingly powerful machines to aid in the sealing of Calamity Ganon, the mightiest being the Divine Beasts Vah Medoh, Vah Ruta, Vah Rudania, and Vah Naboris. Each Divine Beast has enough firepower to level a mountain, and both Ruta and Naboris have godlike dominion over elements to the point of being able to alter the weather itself over a certain radius. Weaker, but still powerful are the Guardians, an army of Cyber Cyclops war machines that are spawned en masse by a series of four towers. Despite effortlessly defeating Ganon, the king of Hyrule feared these machines and banished the Sheikah before hiding them all away. And sadly, this cruel act of paranoia would be justified when they were unearthed to combat Calamity Ganon when he returned... only for Ganon to take control of them and nearly destroy Hyrule with his mechanical hordes.
 * After seizing control of the Guardians and Divine Beasts, Calamity Ganon would also create a few Mechanical Abominations in his image by combining Sheikah tech and his Malice into the Blight Ganons, four grotesque demons wielding hard-light technology that ..
 * The CORE from Undertale may be this, given the role it played in the backstory of, its creator. In practice it's meant to be a gargantuan underground power plant, but . If a power plant accident can essentially , then what in the world is this thing?!

Western Animation

 * The Robot Devil AKA Beelzebot in Futurama is a prime example, although he does have his limits: he finds sacrificing robot children to be cruel. Bender begs to differ.

Real Life

 * God, we hope not.
 * Being more specific, a common fear is that developments and advances made in the fields of artificial intelligence may lead to humanity facing down their own Skynet sometime in the future.