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. Of course, said entity need not be wholly mechanical, only primarily so.

This can overlap with 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.
 * Several of them show up in the works of Go Nagai, often overlapping with Giant Space Flea From Nowhere.
 * The Great Emperor of Darkness,, is the Big Bad of Great Mazinger.
 * In the Shin Mazinger Zero manga, we have.
 * Shin Getter Robo, created by both Nagai and Ken Ishikawa, has an example that is immensely powerful. Its sheer size dwarfs planets, its mere passing destroys worlds, and it is rumored to be capable of devouring a whole universe. One single beam can blow a planet to cosmic dust, and its fist can tear the fabric of time-space. Vast armies have stood against it and fallen without inflicting so much as a scratch. Its name?
 * The final enemy fought in Digimon Tamers is the D-Reaper, a data-disposal program that was both man-made and technological in origin, and found itself plugged into cosmic power. To fulfill its objective - a null-state for everything - it mutated into more and more alien forms, all inspired by the Cthulhu Mythos (mixed correspondingly with designs of the Angels from Evangelion). It got worse when D-Reaper became aware of humans as entities; it tapped into the agony and pain of one little girl, amplifying and becoming The Heartless - which drove it quite insane by anyone's standard.
 * The titular mech of Tengen Toppa Gurren Lagann. It can only exist in a special space between dimensions, is impossibly large, and both it and the Grand Zamboa are able to weaponize galaxies. It's pretty much a giant robot that doubles as an Energy Being.
 * Magical Girl Lyrical Nanoha A's has the Darkness: an immortal, dimension-hopping, dimension-breaking, constantly morphing, bio-mechanical monstrosity that appears when you fill up all 666 pages of the Book of Darkness. If you manage to temporarily kill it, it will only rejuvenate in another dimension, where it will tempt another mage to fill up the pages of the Book of Darkness again, allowing it to be unsealed and go on another rampage. Magical Girl Lyrical Nanoha ViVid showed through flashbacks that, during the time of the Ancient Belka War when it was most active, doomsday cults worshipped it as a god. The scariest part? Magical Girl Lyrical Nanoha A's Portable: The Gears Of Destiny revealed that the Book of Darkness was originally created by the Precursors as a seal for an even worse Eldritch Abomination called the Unbreakable Darkness.
 * Star Driver: is a Humongous Mecha that's incredibly big even when compared to other Cybodies. Why?.

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. The music video for his hypothetical theme shows him in action:
 * SHIVA from the 1990s-vintage Mega Crossover fic The Dance of Shiva. It started out as an AI computer, created as an assistant by a Mad Scientist easily equal to Washuu from Tenchi Muyo! Ryo-Ohki -- but after its creator was executed for arranging two simultaneous Class 4/5 Planetary annihilations of inhabited worlds (just so he could compare their results and relative effectiveness), SHIVA merged with a genuine Eldritch Abomination and became something close to a mad, evil god.

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.
 * The entire plot of The Matrix involves the concept of an evil AI using humans as batteries, keeping them in a virtual Lotus Eater Machine to eliminate any chance of resistance or rebellion.

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.

Urban Legends

 * The myth of Mariana's Web; some people seem to think the Internet itself has an Eldritch Location where you'll find Things Man Was Not Meant to Know.

Video Games

 * Okami gives us the Final Boss of the game:.
 * 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.
 * The Legend of Zelda franchise:
 * 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 ..
 * In Hyrule Warriors: Age of Calamity,
 * Undertale:
 * The CORE 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?!
 * Then there's one of the Final Bosses:
 * Deltarune has the Bonus Boss of Chapter 2 and . Said boss is a Walking Spoiler of an example, so the explanations below will be quite lengthy - proceed at your own risk.
 * In the Normal/Pacifist route:
 * The titular Insanely Twisted Shadow Planet was created by a small Eldritch Abomination that assimilated the Sun and turned it into a bio-mechanical shadow-like monstrosity..
 * The titular Insanely Twisted Shadow Planet was created by a small Eldritch Abomination that assimilated the Sun and turned it into a bio-mechanical shadow-like monstrosity..

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.
 * Unicron, in most versions of Transformers; like Galactus, but a robot. In fact, even in his first appearance, he's called a "monster planet" right from the getgo, and when he assumes his true form, it makes clear what he's supposed to be, given his claws, horns, wings... He's The Devil, for pete's sake! In all but name, anyway.

Real Life

 * 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.