Eldritch Abomination/Live-Action TV

Examples of s in include:

Buffy the Vampire Slayer

 * The tentacled monstrosity underneath the Hellmouth is implied to end the world if it were ever released, which almost happened twice, with the heroes barely preventing it.
 * Glorificus, better known as Glory, of season five. Sure, we saw her as a Humanoid Abomination, but that's just because she was a Sealed Evil in a Can. She's a hellgod and was so horrific that other similar gods sealed her and banished her from their dimension. Even in this form, she's an unkillable monstrosity that rips out and eats the sanity out of people unfortunate enough to run into her.
 * Illyria in Angel is from a time when the world was ruled by those like her, who saw (and caused) the deaths of innumerable lesser beings and casually travelled between all dimensions, and dismisses the Bigger Bads as inconsequential. While she spends her appearances in the series possessing Fred's body, her true form is seen in Angel: After the Fall.
 * The Season 8 comics have Sephrillian. And Fray gives us Neauth, Boluz, and Vrill. And the EU Dark Horse comics showed Ky-laag and Azogg-Mon.
 * The First Evil, the origin of all evil in the Buffy-verse.
 * That thing from season 7 who told Giles and Anya about The First. It's composed of sentient eyes and lives in a dimension outside time and space. And it's Sophisticated As Hell.

Doctor Who

 * The eponymous creature in "Image of the Fendahl"; everyone who saw it died of fright, and that was only a crippled ghost of its true self, 12 million years dead. In the Doctor Who Expanded Universe, the Time Lords deliberately created the Fendahl Predator, a malign void which could reach across time and space to feed on the stuff of thought and hungered to devour all eternity, from the Big Bang to the end of time. Those who looked at it saw an endless procession of grotesque images, as their mind struggled to comprehend the incomprehensible. And then the Time Lords released it to use for warfare.
 * The Beast from "The Impossible Planet"/"The Satan Pit", so much so that the Doctor refuses to understand it. It's very much implied to be the literal Devil.
 * In Torchwood, we meet its son, Abaddon, who also counts. (Interestingly, the Beast claims that "Abaddon" is one of its names.)
 * The eponymous Big Bad in "The Curse of Fenric" could definitely count as an Eldritch Abomination, albeit . One of the spinoff novels actually identifies Fenric as
 * The Doctor Who Expanded Universe also says the TARDIS itself is an Eldritch Abomination, which considerately disguises itself to avoid reducing the passengers to gibbering wrecks. As a living shape-shifting creature, at home in extra-dimensional spaces, with a mind even the Doctor deems unfathomably alien, it's certainly a good candidate. A minor story even comments on the TARDIS' mind as completely and utterly.
 * The...creature from "Midnight". We don't see much of it, so it's nothing definite. But it
 * There's a lot of evidence pointing towards the Time Lords being an entire species of this trope, given their incredible age and intelligence and how easily and often the very laws of reality are twisted like playthings by them. Indeed, several of the conflicts between the Doctor and the Master play out a lot like battles in an endless war between two Eldritch Abominations, with the poor lesser beings caught between.
 * If they weren't this initially, then, given the Doctor's description and the events of "The End of Time".
 * On that note, remember the Doctor's line from "The Pandorica Opens" about the thing the Pandorica was designed to hold: "There was a goblin, or a trickster... or a warrior... A nameless, terrible thing, soaked in the blood of a billion galaxies. The most feared being in all the cosmos. And nothing could stop it or hold it, or reason with it. One day it would just drop out of the sky and tear down your world."
 * An assortment of Eldritch Abominations apparently rose from the midst of the Last Great Time War, such as the Skaro Degradations, the Nightmare Child, the Horde of Travesties, and the Couldhavebeen King with his armies of Meanwhiles and Never-weres.
 * The Eternals, beings that live outside of time in eternity, are immortal and use the imagination of people from our universe (they call us Ephemerals) to form realities. They can take anyone they want from any point in time and force them to do whatever they wish. They are not invincible, though; if somehow trapped in our reality, they are mortal and vulnerable.
 * The Ancient Old Ones, beings from the previous universe that follow different physics, which allows them vast Reality Warper abilities; this can be inverted with beings from the next universe that have similar powers.
 * The Nestene Consciousness, a formerly squid-like, later molten energy being that can control plastic, which is, according to the Expanded Universe, one of the thousand children on Shub-Niggurath.
 * Sutekh, Last of the Osirans, from "Pyramids of Mars". At the time, the Doctor describes him as the worst threat he has ever faced, the greatest time of peril in the history of the Earth, and given his awakening would have rendered the planet a barren wasteland before he spread across the universe to kill everything, his concern was very much justified.
 * The Animus from "The Web Planet". In the Expanded Universe, it's actually one of the Great Old Ones from the Cthulhu Mythos.
 * The Weeping Angels: impossibly fast creatures, indistinguishable from ordinary statues until you look away, able to transport people through time, reproduce via Mind Rape, and.
 * The Great Intelligence, from "The Abominable Snowman" and "The Web Of Fear". Acting through its "agents", the Yetis, and never directly, it functions as the Bigger Bad for these serials.
 * The House from "The Doctor's Wife", a malevolent, ancient living asteroid that eats TARDISes.
 * The Sarah Jane Adventures has had "ancient lights", Hive Queens to at least part of the universe that existed before the Big Bang.
 * The Abomination. In this case a Brown Note painting and not a flesh and blood being.
 * The Trickster, part of a Pantheon, whose sole motivation is to cause chaos in the universe at large.

Star Trek

 * Admittedly, this may be special pleading, but the original Star Trek may have had one in the form of the Doomsday Machine, of the episode of the same name. Think about it: a bizarre ship appears from outside the known Galaxy that is irregularly shaped, looking something like a giant cone irregularly carved out of granite, with an abominable eye at its center looking suspiciously like a gateway to hell. It's virtually indestructible and is capable of destroying and consuming whole worlds. Consider also Commodore Decker's response to it: after it destroys his ship and kills his crew, this man, previously an atheist, describes it as the devil and coming straight out of hell and suffers a complete Heroic BSOD. Later, recovering only slightly, his only response is to mindlessly try to attack and destroy it no matter the cost. Failing utterly at this, he surrenders himself to its power and steals a shuttle specifically to fly into it and kill himself. Brr, man.
 * A stronger case can be made for Redjak from "Wolf in the Fold", a formless creature that feeds off pain and suffering. When it possesses the ship's computer, the view screens show a bizarre multicolored, constantly shifting chaos that Kirk speculates is where it comes from.
 * A case could be made also for the Crystaline Entity from TNG. It's a large, amoral being that they can't understand or communicate with, and it destroys every living thing it encounters.
 * Let's not forget that sentient white blob that takes over the cargo bay in Enterprise.
 * What about the guy at the center of the galaxy in Star Trek V? Eldritch enough to pose as God.
 * Hell, what about Q. Sure, he shows up as human, but it's made clear that he could show up as Cthulhu if he so wanted.
 * And on the occasions when humans and similar beings are taken to the home of the Q, the Q Continuum, they are explicitly told that what they perceive is not the reality of the Continuum, but merely a convenient metaphor for something nothing on their level could begin to comprehend.
 * "The Immunity Syndrome" featured an 11,000 mile long space amoeba that 400 Vulcans (and their computer) could not fathom, drained the life force of every living creature (presumably - and ironically - down to microorganisms) in an entire solar system, and was surrounded by a moving zone of space in which the laws of physics were fundamentally altered.

Other Shows
"Castiel: This is... a vessel. My true form is approximately the size of your Chrysler building. Dean: Alright, alright, quit bragging."
 * Power Rangers contains a whole stack of them, occurring at a rate of about one per season. There was Lokar, Master Vile, Maligore, Dark Spectre, Queen Bansheera, Master Org, the Master, Omni, Dai Shi, and probably a few others. But one of the greatest things about the Power Rangers is that the vast majority of these characters share a single thing in common. They got the attention of the Power Rangers, and the Power Rangers killed the hell out of them.
 * Names from Super Sentai originals that inspired Power Rangers: there's Black Cross Fuhrer, Underground Emperor Zeba, and Absolute God N.Ma.
 * Babylon 5 featured a race of ancient aliens that were a kind of Eldritch Abomination in the TV-movie 'Thirdspace', inhabiting a different type of space (neither normal, nor hyperspace) and waiting for a very, very long time until someone finds the Artifact of Doom and activates it, allowing them to be released. Oh, and they have tentacles and extremely strong telepathy, and they cause insanity. Even in the Vorlons. According to the RPG, they move like locusts from reality to reality, devouring and using up each in turn before moving from the ruins of the last to their next prey; the mere psychic shadow of their ancient depredations INSPIRED Lovecraft and analogous authors, not to mention several varieties of cultists, in other intelligent races.
 * In the Season One episode 'Mind War', Catherine Sakai is investigating a planet while looking for a rare ore, and her ship's engines are overwhelmed by the mere presence of an unknown alien ship. She is only saved because G'Kar suspected what would happen, as that planet was known to be dangerous, and sent two fighter ships to rescue her. When she asks G'Kar what she saw out there, he makes an analogy using an nearby ant that's listed in the quote page.
 * In fact, pretty much all of the Babylon 5 First Ones are this...some more than others.
 * Already touched upon in the Literature section, but the made-for-TV film adaptation of The Langoliers is pretty traumatizing if you had the misfortune of seeing it as a child.
 * Charmed had "The Nothing", a creature imprisoned inside another dimension (located in an ice cream truck). It's been put to good use by devouring demon children.
 * There's also The Hollow, an ancient entity that exists simply to consume power. It can possess any living being and use it to absorb all power. It's said that if it is let loose long enough, it will consume everything. The threat was so great that Good and Evil had to join forces to seal it away..
 * Some Monsters Of The Week from Ultra Series fit this trope. Notable is Ultraman Tiga, where Ghatanothoa appears as the Big Bad. However, these are Superhero shows that punch out Cthulhu on a weekly basis.
 * Another good example is Gan Q from Ultraman Gaia. It is a bipedal giant eye with many smaller eyes all over its body. Coming from another dimension, Gan Q found everything on our side funny, especially when things got destroyed. It also has a Psychic Power that can drive people mad just by sight. Its never-ceasing laughter doesn't help either.
 * True form Angels in Supernatural. Physically, they (to each other) meet the descriptions of them in religious literature. People who look at an angel in his true form have their EYES BURNED OUT. They inhabit human vessels to be able to interact with other humans safely, however. It's notable that they're one of the few, if not only creatures fitting the definition of an Eldritch Abomination in this series, as the other adversaries are almost all Humanoid Abominations.