%% Image selected per Image Pickin' thread: http://tvtropes.org/pmwiki/posts.php?discussion=1379261033074475900
%% Please do not replace or remove without starting a new thread.
%%
[[quoteright:350:[[Film/TheDayTheEarthStoodStill2008 http://static.tvtropes.org/pmwiki/pub/images/rsz_stadium_7627.png]]]]

->''Imagine you're like the fabled King Midas, and you have the power to convert matter with a single touch. Except that instead of gold, everything you touch turns into shit. And everything it touches turns to shit. Before you know it, the whole world is shit, and it's all your fault.''
-->--'''Website/{{Cracked}}''' on [[http://www.cracked.com/article_16583_the-5-scientific-experiments-most-likely-to-end-world.html#ixzz2LzKbkvgM Strange Matter]]

Grey Goo is like a HordeOfAlienLocusts, only replace Alien Locusts with {{Nanotechnology}} -- and instead of grass, they "eat" ''anything.'' Or, if the protagonists are lucky, just anything mineral or electronic.

They're worse than alien locusts. Grey Goo destroys resources by turning them into more grey goo -- more {{nanomachines}}. It's TheVirus for nonliving things -- though it may be able to take down living things as well, and likely will turn them into nonliving things if they're in the wrong place. In theory, you can end up with a planetary body made of nothing ''but'' grey goo. Physical laws regarding energy, thermodynamics and the like stand in the way, but even a partial success in this case is likely to suck for everyone involved.

For some reason, most of the time these specifically were created to clean up oil spills.

Can cause TheEndOfTheWorldAsWeKnowIt -- specifically, Type 3b or 4 on ApocalypseHow.

Compare BlobMonster.

----
!!Examples:

[[foldercontrol]]

[[folder:Meta]]
* [[BrowserNarcotic How many tabs do you have open,]] [[WikiWalk and how many new tabs spawn from each of those tabs,]] [[TVTropesWillRuinYourLife and how much of your time have they devoured?]]
[[/folder]]

[[folder:Anime & Manga]]
* The titular creatures in ''Manga/{{BioMeat|Nectar}}''.
* Grey goo has completely devoured Mercury by the time of ''Manga/{{Gunnm}}'' (AKA ''Battle Angel Alita'').
* The ''WORMS'' in ''Anime/SkyGirls'' are related to this. Sort of.
* ''Franchise/{{Gundam}}''
** ''Anime/TurnAGundam'' features Black Goo in the form of the Moonlight Butterfly (''Gekkōchō''), which is named because it manifests as giant shimmering energy contrails that emerge from the titular HumongousMecha's back like wings. The nanomachines only target technology, but do so on an immense scale; the last time the Moonlight Butterfly was used, it sent humanity into a Dark Age that they're still recovering from (when the series begins, technology is roughly on par with the early 1900s).
** In Creator/YoshiyukiTomino's original novel, the ''full powered'' version of the eponymous Gundam can affect the area from Earth to Jupiter with the Moonlight Butterfly - that's '''over 600 million miles'''.
** The DG Cells in ''Anime/MobileFighterGGundam'' are a combination of this and TheVirus, though strangely enough they were designed to be ''beneficial'', as their original purpose was breaking down dead or decaying matter and using it to foster new life. [[spoiler:The Devil Gundam instead uses them to reanimate dead humans under its control, or infect live humans and MindControl them.]]
* The [[BigBad D-Reaper]] from ''Anime/DigimonTamers'' is a very slow form of GreyGoo, breaking down inorganic matter and reconfigure it into its various agents once it emerges in the real world. It's depicted as a mass of ''red'' goo in the series because its actually super-heated to extreme temperatures by accelerating its particles [[YouFailPhysicsForever beyond the speed of light]].
[[/folder]]

[[folder:Comicbooks]]
* What happened to [[spoiler:Negaduck]] after [[LiteralSplitPersonality being hit by the Tron-Splitter]] at the end of the ''ComicBook/DarkwingDuck'' story "Crisis On Infinite Darkwings".
* Adam Warren's adaptation of the ''ComicBook/DirtyPair'' revealed that the Earth had been destroyed decades earlier in a massive Grey Goo outbreak, the "Nanoclysm", which led to nanotechnology being regulated and virtually outlawed. The villain of the miniseries planned to use a cache of nanotech to take over HeroesRUs's Central Computer, and from there, the known universe. [[spoiler:Unfortunately, the Central Computer revealed that it was partially based on something the Nanoclysm left humanity as an apology…]] His later ''{{ComicBook/Empowered}}'' had a Grey Goo eruption that created {{Sexbot}}s, for reasons too complicated and silly to explain but which involved someone trying to use alien nanobots with an untranslated interface for perverse purposes.
* ''ComicBook/TheFilth'' features creatures like this, but portrays them in a very sympathetic light during the stages of their evolution. The more they spread, the more the world is seen from their perspective.
* The Modular Man from ''ComicBook/TomStrong'' is a hi-scale example of this. Each individual module is about the size of your head. Once he gets to Venus, though, he multiplies until he has something closer to the proper Grey Goo appearance.
* ''ComicBook/{{Transmetropolitan}}'' mentions it as a possible weapon if the commonly-used "makers" are reprogrammed. The standard MO for handling a "grey goo" scenario is to release "blue goo" (disassembler nanites that degrade matter -- all matter -- to the point where Grey G can't make more nanites out of it, and then destroy the Grey Goo nanites) to contain the grey goo and restrict its damage to a small area. One brief mention is made of someone who lost his legs because he decided to (and succeeded) shut off the grey goo instead of releasing the blue goo.
* One of the early comic issues of ''Magazine/{{MAD}}'' had the planet Mars consumed by the Gookum, a jelly-like pink substance which eats anything organic, and, worse, ItCanThink. It stays dormant for 500 years at a time, and the joke/Mandatory Pulp Sci-Fi Twist is that cherry Jello parfait is completely indistinguishable from dormant Gookum. One day... one day the Gookum will quiver, will stir...
* One issue of ''ComicBook/FantasticFour'' claimed that the reason [[ReedRichardsIsUseless Reed has never tried to market]] the unstable molecules the team's suits are made out of is that if a careless person gets ahold of the stuff and pokes it the wrong way with an electron microscope, it starts destabilizing all surrounding matter into an ever-expanding blob of goo.
* ''Comicbook/IronMan'''s Technovore is a nanotechnological entity driven to assimilate and integrate foreign technology into itself.
[[/folder]]

[[folder:Films]]
* ''Film/TheDayTheEarthStoodStill2008'' tries to reboot the Earth with this. It was more a "Grey Cloud" than Goo, but same strategy.
* ''Film/GIJoeTheRiseOfCobra'' had "Red[=/=]Black" weaponized Goo (which is [[SicklyGreenGlow green for the viewer's convenience]]), which ate any metal it came into contact with. Thankfully, the designers were smart enough to build them with cutoff switches which neutralized them instantly. It also had a limited life span which meant that if it's food source was too far away it couldn't make it, depending on how much of a start it got. Eating the Eiffel Tower would give it enough of a start to devour all of Paris, but it would likely die out before it reached another city. Devour [[spoiler: a single ship high in the stratosphere]] and it dies out long before it reaches anything else. It's unlikely that the nanomites were self-replicating at all. A self-replicating nanomachine is by necessity, much more complex that a simple molecular disassembler. And if you're foresighted enough to build in a kill-switch, the very last thing you'd want to risk is the possibility of generational copying errors disabling that function.
* ''Film/TheBlob'' (in the original 1958 movie) ''could'' be either this or TheVirus. No one's really ever gotten close enough to examine it without being eaten. All that's known about it is that it's of alien origin. Oh, and it prefers to devour ''organic'' life as opposed to inorganic matter. The 1988 remake of the movie had the Blob be the spawn of a secret government germ warfare project. There it acted less like mindless spreading Grey Goo and more like a malicious, semi-intelligent monster.
[[/folder]]

[[folder:Literature]]
* ''Century Rain'' by Creator/AlastairReynolds has Earth effectively uninhabitable from the effects of rogue swarms of nanobots. The nanobots were originally created to affect weather patterns, but they were corrupted. New bots were created to fight those, which went rogue, and so on and so forth. The survivors from the disaster, who now reside in orbital habitats, ''weaponized'' the Grey Goo and use it as a weapon of mass destruction. Something similar happens in his Literature/{{Revelation Space|Series}} universe, where [[spoiler: The Greenfly terraformers go rogue and will inevitably consume the entire universe.]]
* One of the best examples is Wil [=McCarthy=]'s ''Bloom'', a novel set in a future where the last fragments of humanity lives in habitats in the asteroid belt and in jovian orbit, after the entire inner solar system was devoured in a Grey Goo incident. Earth, Venus, and Mars are now large fuzzy balls of nanotech, nanotech solar sails drift aimlessly throughout the system, and occasionally errant strands drift out on the solar winds and try to devour anything they touch in the outer solar system. [[spoiler:It's okay, though, because the billions of people devoured in the incident are merely compressed, not gone, and their brain engrams still survive in the bloom, immortal and living in virtual paradises of their own construction; imagine how powerful a computer would be if it was made from an entire solar system?]]
* Another über-example would be Charles Stross' ''Literature/{{Accelerando}}'', where pretty much the same events as in ''Bloom'' happened ''deliberately, and for the betterment of mankind''.
* The novel ''How to Mutate and Take Over the World'' ends with [[spoiler:nanites from a dessert factory transforming the world into key lime pie. And this gets spoiled about a third of the way in, [[NoFourthWall in a fictional review of the book]]]].
* In one of the ''Literature/ThursdayNext'' novels, Thursday's time-traveling father tells her of a future wherein the world was overtaken by such a scenario; the world is consumed by pink slime. [[spoiler:It turns out to be strawberry pudding.]]
* ''Literature/DeathFromTheSkies'' by Phil Plait presents a berserker Von Neumann probe, which is essentially grey goo on a cosmic scale.
* Neatly inverted in Charles Stross' ''Literature/SaturnsChildren''--robots think of organic life as "pink goo," reproducing without limit.
* In Scott Westerfeld's book ''[[Literature/{{Uglies}} Specials]]'', the main characters break out of a weapons storage facility using nanotechnology-based silver goo (much more flashy and dramatic than plain old gray goo, to paraphrase the author).
* A rather spooky example [[http://qntm.org/gorge presented here as a story]], [[spoiler:which shows us why you should just let the gray goo be...]]
** And played with in [[http://qntm.org/transit this story on the same site]], [[spoiler:where the sentient gray goo triggers the nanoapocalypse to ''save'' humanity from an impending asteroid collision.]]
* Charles Pellegrino and George Zebrowski's ''Literature/TheKillingStar'' includes weaponized Grey Goo which is used to [[spoiler:pick off one of the few surviving outposts of humanity.]]
* Creator/GregBear:
** In ''The Forge of God'', this is done deliberately and systematically by a belligerent alien race, to humanity as well as at least one other race. The sequel, ''Anvil of Stars'', is the story of a handful of the survivors of Earth -- specifically, the children -- seeking out the race that destroyed Earth, to enact [[EarthShatteringKaboom the Law]].
** In Greg's ''Literature/BloodMusic'', the Green Goo is not nanotechnology, but biotechnology, but operates in basically the same fashion. The "noocytes" consume all the biomass in North America, converting it to more noocytes. [[spoiler: It turns out that all the living creatures who are assimilated are also recorded and "alive" in a new kind of reality, similar to "Bloom" above.]]
* The Melding Plague also ended humanity's golden age in Creator/AlastairReynolds' ''Revelation Space'' series. Everybody was enjoying the benefits of a [[MagiTech highly advanced nanoscience]], until humanity encountered a plague that could subvert all but the hardiest [[NanoTech nanotechnology]]. Such subversion has disastrous consequences for the device in question, anything to which it was attached, and potentially anything nearby. This is partly used to justify the somewhat SchizoTech nature of the setting.
* Played with in ''TheDervishHouse'' by IanMcDonald. The Grey Goo scenario is a common fear in the near-future setting due to a famous scientist's doomsday predictions of a nanotech catastrophe, even though it's generally accepted that he was just fearmongering and was wrong. A character later comments that the Grey Goo scenario ''has already happened''; it's called organic life. It turns out that [[spoiler:self-replicating nanotechnology is key to a massive terrorist attack, but not in the traditional sense]].
* [[spoiler:''Literature/DeltoraQuest'']] has a literal grey goo flood final XanatosGambit IfICantHaveYouNobodyCan result of the Shadow Lord's plans. It was designed to kill everything on the continent.
* In the ''Franchise/StarWars'' RPG supplement ''The Unknown Regions'', a Grey Goo named Mnggal-Mnggal is mentioned. It is sentient, and able to infect any form of matter, as well as take control of creatures as 'zombies'. Its origins are unknown, and it's likely biological. Note: If there was a trope for biological Grey Goo Mnggal-Mnggal would fit there.
* In Creator/JackMcDevitt's ''[[Literature/PriscillaHutchins Chindi]]'', an ancient alien satellite that has already mysteriously destroyed one ship is being much more carefully investigated by a second when the ship begins to come apart. It turns out that the satellite uses grey goo to repair/replicate itself, and the ship is being eaten. Several people die, and one, the artist with a big crush on Hutch, is rescued just in the nick of time.
* In Creator/JohnCWright's ''Literature/CountToTheEschaton'', the Savants used Golden Goo. It destroyed the cities, where it was released first -- killing most people there, with only a few stunned to be transferred with their minds intact -- and only by savage, fiery attack by the Giants was the earth saved from their "Golden Age."
* In Creator/WalterJonWilliams's ''Literature/{{Aristoi}}'', a form of grey goo (called "mataglap nano") destroyed EarthThatWas. As a result, only the eponymous Aristoi are legally allowed to use nanotech freely and they are fanatically paranoid about the possibility that any given form of nanotech could somehow mutate into mataglap.
* In the short story ''[[http://clarkesworldmagazine.com/mellor_09_13/ Mar Pacifico]]'' by Greg Mellor, nanotech designed to fight the effects of global warming (by letting the oceans absorb more carbon) sweeps over the Earth absorbing most forms of life. [[spoiler:When the protagonist is absorbed, she discovers that humanity still exists as a linked HiveMind inside the nanotech.]]
* In SA Swann's Literature/TerranConfederacy universe, the human colonies on Titan and the outer moons were devoured by a Grey Goo swarm, leading to Main/{{Nanomachines}} being made one of the Heretical Technologies. The Confederacy and its successor states continued this policy, enforcing it with things like [[ColonyDrop hundred kilometer asteroids]]. ItsTheOnlyWayToBeSure!
[[/folder]]

[[folder:Live-Action TV]]
* A failed pilot for a TV series called ''Doorways'' by Creator/GeorgeRRMartin featured a parallel dimension where, yep, nanomachines used to eat up oil spillages went and ate all the oil. This scenario was the result of ExecutiveMeddling -- G.R.R.M's original script (and the one found in his "Dreamsongs" retrospective compilation) featured the parallel Earth as a [[SingleBiomePlanet Winter World]], but this was apparently too bleak for a first episode.
* The Replicators of ''Series/StargateSG1'' are this trope scaled up to lego size. When they eventually [[MechanicalEvolution evolved]] to silver goo, their diet changed from "any kind of metal" to "[[{{Unobtainium}} neutronium]] only", thus keeping the new model [[TooAwesomeToUse a rarity]].
* A minor example of this was the nanite colony Wesley Crusher was running in one episode of ''Series/StarTrekTheNextGeneration''. Fortunately, this goo turned sentient and was willing to be moved to a better food source before it disabled the ship.
* The main villain of the second season of ''{{LEXX}}'' worked on a bigger scale, commanding a legion of drones that could tear anything apart and convert it into more drones. [[spoiler:Eventually all mass in the universe is converted into drones.]]
[[/folder]]

[[folder:Radio]]
* The old LightsOut radio serial had "Chicken Heart", a biological grey goo that started out as a cell culture from [[ExactlyWhatItSaysOnTheTin a chicken heart]] and turned into some kind of mindlessly spreading cancer blob that quickly overwhelmed the research lab, university, and city that it was created in. Even worse, [[OnlySaneMan the researcher responsible]], escaping with a reporter in a plane, knows [[NukeEm exactly how to stop it]], but [[TheCassandra the authorities refuse.]] [[WeirdAlEffect Somewhat more famous]] is Creator/BillCosby's Jell-O-soaked retelling as he remembers hearing it on the radio as a kid.
[[/folder]]

[[folder:Tabletop Games]]
* Gray Goo is discussed in ''TabletopGame/{{GURPS}}: Ultra-Tech'' in a section on Von Neumann machines and points out the waste heat of the goo eating a planet is likely a more pressing threat than being eaten by it. On the up side they require extremely high level technology and are expensive to make, on the down side some versions might be able to fly or travel through space.
* ''Centauri Knights'', a far future/HumongousMecha sourcebook for ''TabletopGame/BigEyesSmallMouth'', takes place on a dead alien planet colonized by humans. According to the GameMaster information in the back, the reason the planet was vacant was because an ancient war resulted in a Grey Goo superweapon accidentally being unleashed upon the planet (the game even explicitly uses the term "Grey Goo" to explain the phenomenon).
* Virus Bombs of ''TabletopGame/{{Warhammer 40000}}'' work on a similar principle to the Red or Black Goo scenario noted above. The Imperium utilise them in dire situations when [[TheEndOfTheWorldAsWeKnowIt a problem can only be solved by destroying a planet]].
* ''TabletopGame/DungeonsAndDragons'' has this in the form of green slime, which converts anything it touches into more green slime. (Except stone, which is immune to it, and wood is more resistant than most. It dissolves metal ''very'' fast, however.) Fortunately, it's immobile, so you can avoid it if you just stay away from it.
[[/folder]]

[[folder:Videogames]]
* ''VideoGame/TastyPlanet'' is a game based on Grey Goo where a cleaning agent gets bigger and bigger as you guide it through the levels starting on a Petri Dish until it eats the planet, then the solar system, galaxy, universe, space and time! [[spoiler:Then it explodes and everything starts over.]]
* The last "secret" life form class on ''VideoGame/SimEarth'', [[MechanicalLifeforms robots]] (unlocked by [[NukeEm bombing a Nanotech-class city]], fittingly enough), are very well-suited for survival. By this, it means that they reproduce rapidly, they can live in any habitat - even the ocean - and thus can spread across the entire map with little effort, competing against organic life [[CurbStompBattle can't even be called a competition]], and - oh yeah. [[NighInvulnerability They're immune to disasters]], even ones activated by the player. [[AIIsACrapshoot All organic life on your planet will quickly go extinct when these guys show up]].
* The TrueFinalBoss of ''VideoGame/SuperRobotWarsOriginalGeneration'', [[spoiler: Septuagint]], can be seen as this. It may be more of [[spoiler: purple crystals]], but its directive is clear: exterminate the whole world by consuming anything to come to its path, and it can even make [[spoiler: crystal-based]] duplicates of things it has consumed.
* In the ''Franchise/MassEffect'' games, you can find a planet called Zaherux, which is covered with seas of silicon. The flavor text mentions that a popular extranet meme says that the oceans are actually a huge swarm of 'disassembler' nanites.
* Biological version in ''VideoGame/{{Outpost 2}}: Divided Destiny''. A terraforming microbe runs wildly out of control, breaking down organic matter, among other things, and forcing both colonies on the planet to try to evacuate-one of the rare versions in which the Goo truly is unstoppable, though one colony can delay it briefly, and the omnipresent threat during the campaign.
* In ''VideoGame/HostileWaters'', the "alien" antagonists have a [[strike: grey goo]] Disassembler cannon. It fires at a city and reduces it to mush. It's up to you to blow up the cooling radiators before it fires its third salvo and destroys Central, the world capital. Once you do that, the next shot blows it to hell and spreads disassemblers throughout their base.
* In the [[http://www.youtube.com/watch?v=4_0ZzwptEUI intro cutscene]] of the video game ''VideoGame/DeusExInvisibleWar'', a terrorist employs a "Nanite detonator" in Chicago, [[DoomedHometown destroying the city]]. And in the first ''VideoGame/DeusEx'', the [[spoiler:Gray Death is revealed to be an artificial plague]].
** In Invisible War, there are also "nanite swells" - clouds of nanobots whose origin isn't entirely clear, but which present a serious environmental hazard and are responsible for the poor health of people forced to live outside protected cities. It's never made entirely clear if these are actually self-replicating or just the remains of weapons or experiments used during TheEndOfTheWorldAsWeKnowIt.
* In ''VideoGame/SidMeiersAlphaCentauri'', one of the Special Projects shows the video of several containers placed on the site of a battle, littered with debris and dead bodies. The containers open, releasing nanites that look like glowing goo. They proceed to consume everything in sight, including the dead, and use the materials to create a brand-new HoverTank.
* Tiberium in the ''Franchise/CommandAndConquer'' universe can be seen a slow-acting example of it. It needs around half a century to engulf a significant portion of the Earth.
* Grey goo missiles called the "Nano Virus" are a high-level planetary siege weapon in ''VideoGame/SwordOfTheStars''. It is amusingly classified as a bio-weapon, meaning you have to go through several tiers worth of gene modification to access it. The Nano Virus is harmless to organics, but the planet's industrial output will be heavily damaged and it will wipe out an AI rebellion as if they were living creatures hit by a regular bio weapon. It is the only bio weapon that will affect the Zuul, since their machinery is made of the same metal as everyone else's.
* ''VideoGame/ParasiteEve'' features massive amounts of Pink Goo. The BigBad is actually a PatientZero infected with intelligent pink goo by accident. Every enemy in the game was created by the pink goo. If you go on to the Chrysler Building in the [[NewGamePlus EX game]], the building itself is infected with the pink goo (which is the in-world reasons that mode has random maps) and pink goo is literally everywhere.
* A grey goo like attack is possible in ''VideoGame/SupremeCommander2''. The Cybran Nation can upgrade their engineers to have weapons, by doing this and building nothing but engineers you will get an ever growing blob of engineers that will automatically shoot every enemy in sight and use the remains to build more engineers. [[http://www.pcgamer.com/2010/06/20/engineering-victory-in-supreme-commander-2/ Full instructions here]].
* In [[SuperSmoke Smoke's]] ending in ''VideoGame/MortalKombatArmageddon'', the power of [[ElementalEmbodiment Blaze]] causes his nanobots to go into overdrive, consuming all of Edenia and replacing it with a sentient mass of grey goo that calls itself Smoke.
* The Vasari from ''VideoGame/SinsOfASolarEmpire'', who specialize in Nanotechnology, have ships that are able to throw blobs of destructive nanobots at enemy ships.
* Provides the backstory and setting for ''VideoGame/{{Hawken}}''. In the endless CorporateWarfare on the planet Illal, one of the three dominant {{Mega Corp}}s collapsed, triggering a self-replicating nano virus that converts the environment into a labyrinth of patchwork metal--known as the "Giga Structure" and "Hawken Virus." At the time of the game's launch, the virus covered a third of the planet.
* The EldritchAbomination Deus from ''VideoGame/{{Xenogears}}'' is upgraded from a simple biological weapon into a living mass of GreyGoo by the game's BigBad Krelian through nanomachines.
[[/folder]]

[[folder:Webcomics]]
* [[http://xkcd.com/865/ This]] page of ''Webcomic/{{xkcd}}'' jokes about how [=IPv6=] is perfect in that the nanobots will only be able to devour about half the planet before they run out of addresses.
* Hostile nanoswarms are so common in ''Webcomic/SchlockMercenary'' that there's standard-issue tactics and equipment to stop them; people worried about nanobot infection drink nanotech-fighting chemicals to control them, "nanofilm" is routinely employed to control rogue nanobot swarms, and worst comes to worst, the nanobots will be isolated by ubiquitous AI with gravity-control technology. %%If anyone knows what the employer's name is, feel free to add it in. Go Go Wiki Magic!
-->'''Employer of the month:''' We've all been drinking Nanneze like it was Ovalquik.
-->'''Tagon:''' Careful, that stuff'll kill you.
-->'''Employer:''' What, the Nanneze, or the Ovalquik?
-->'''Tagon:''' ''Both.''
* ''Webcomic/NobodyScores'': When all you have is a jar of nanorobots, [[http://nobodyscores.loosenutstudio.com/index.php?id=56 everything looks like a problem best solved by the application of nanorobots.]]
[[/folder]]

[[folder:Web Originals]]
* In the late 20th century of the ''Literature/ChaosTimeline'', nukes are scrapped because nanobots made them obsolete. The so-called [[GratuitousGerman Braunschleim scenario]] is the casual armageddon scenario everybody fears. [[spoiler:On the eve of WorldWarIII, this fear urges a bunch of {{Playful Hacker}}s to seize control over the military and the rest of the world, in order to prevent the danger of nano annihilation.]]
* In ''WebOriginal/OrionsArm'', humanity's exodus from [[EarthThatWas Old Earth]] was caused by the [[http://www.orionsarm.com/eg-article/4ad4d58752948 Nanodisaster]]. Interestingly, this is a case where the grey goo itself was quickly neutralized by blue goo (nanites created specifically to neutralize grey goo). [[HomeworldEvacuation The Great Expulsion]] was more due to the [[AIIsACrapshoot Global Artificial Intelligence Amalgamation]] created to protect Earth from human technological disasters by controlling said blue goo [[GoneHorriblyRight deciding to protect Earth from human technological disasters once and for all]]. The only choices were to live under strict ecological rules, get the hell off of [[FunWithAcronyms GAIA]]'s world, or face destruction.
[[/folder]]

[[folder:Western Animation]]
* One of ''WesternAnimation/{{Ben 10}}'''s alien forms is Upgrade the Galvanic Mechomorph, a piece of Grey Goo from a planet of sentient Grey Goo that has the ability to separate itself into smaller, independent entities that get less intelligent the more they split. They were created by the series' resident {{Sufficiently Advanced Alien}}s, the Galvans, but developed a mind of their own.
* ''WesternAnimation/{{Futurama}}'':
** Bender becomes this in one episode after installing a MatterReplicator that makes two smaller duplicates.
** ''{{Inverted|Trope}}'' in another episode, in which some nanobots released on a deserted planet first eat some waste oil, then start trying to eat [[{{Fanservice}} clothes]], but soon get bored of that and create an entire ecosystem made of nanobots instead of cells. Where the necessary mass came from is [[ArtisticLicensePhysics left as an exercise for the reader.]]
* Matrix from ''WesternAnimation/{{Gargoyles}}'', a semi-sentient mass of nonobots created by Fox's mother (who mentions the Grey Goo scenario by name) in Australia, tries to bring "order" to the continent by eating and assimilating it. Dingo made a HeelFaceTurn and convinced Matrix to fight for "Law and Order" (Long story involving the Aborigine [[SpiritWorld Dreamtime]], roll with it), so it fused itself with his PoweredArmor. Later, he did provide one of the funniest lines in the comic series on taking over the world.
* In ''WesternAnimation/GodzillaTheSeries'', one of the first MonstersOfTheWeek is a colony of self-replicating petroleum-eating {{nanomachines}} that, inevitably, goes out of control and turns into a Zilla-sized shapeshifting blob on a feeding frenzy.
* An episode of the 1980's animated ''WesternAnimation/TheIncredibleHulk'' involved a scientist bioengineering a BlobMonster that could eat literally anything except the special glass of its container, and would get bigger the more it ate. Of ''course'' the glass breaks and it starts eating Gamma Base. ''Fortunately,'' it turns out that the one thing it's allergic to is gamma radiation, which the Hulk constantly emits.
* The ''[[WesternAnimation/JusticeLeague Justice League Unlimited]]'' episode "Dark Heart" dealt with alien nanomachines that were in the process of taking over Earth this way. Their species appears to be made artificially for a war from fifty-thousand years ago, and is meant to consume every planet they're sent to, spread to some other planets, and repeat until they're all dead.
* ''WesternAnimation/TheTransformers'' episode "Kremzeek!" involved a highly specialized electricity eating spark creature, splitting into new copies of itself as it ate more and more current. The "annoying replicating electrical prankster" is a kids' show plot that really gets around. In the old ''WesternAnimation/{{Teenage MutantNinja Turtles|1987}}'' cartoon, it's called ''The Big Zipp Attack,'' in ''WesternAnimation/TheMightyDucks'' it's "Zap Attack." ''WesternAnimation/{{Ben 10}}'' has the imagination to not name it after the creature: instead of something like ''"The Megawhatts Attack,"'' the critters are first encountered in ''Tourist Trap.'' (We find they're actually an alien race called Nosedeenians.) It's not as obligatory as the FantasticVoyagePlot, but watch enough cartoons and you'll know it by heart.
* One episode of ''WesternAnimation/ThePowerpuffGirls'' features Grey Goo nanobots dropping from a raincloud and destroying Townsville, though the bots thankfully ignored living creatures.
* ''WesternAnimation/CodeLyoko''
** In the episode "Marabounta", Jeremie tried to create a virus that would destroy XANA's monsters, using [[BigGood Franz's Hopper's]] journal and basing it off African army ants. At first the huge blob-like monster seemed to work, attacking and devouring XANA's minions. Then something went wrong, and it tried to attack Aelita. Jeremie realized too late that her connection to XANA was causing it to mistake her for one of the monsters, but by then it was out of control and growing larger by the minute, threatening to consume all of Lyoko. (Leading to one of the most chilling scenes of the series to date, Yumi trying to protect Aelita, only to be devirtualized when she was EatenAlive by the thing.) Fortunately, XANA, who at that point needed Aelita alive to complete his plans, [[EnemyMine instructed his monsters to help the heroes]], and due to the brief alliance, they bought enough time for Jeremie to program and anti-virus that eradicated it.
** An earlier episode "Amnesia", had [[AIIsACrapshoot XANA]] infecting nanobots from a class as an infestation to cause massive amounts of memory loss.
[[/folder]]

[[folder:Real Life]]
* Life itself has spread to every conceivable corner of the Earth (that we have been able to check so far) in the last 4.5 billion years and readily converts non-living matter into living matter through its inexorable reproduction. It is also really, ''really'' difficult to truly sterilize anything. This is sometimes referred to as the "green goo" scenario.
* A strange example from RealLife which has elements of the Grey Goo scenario: In the 1950s scientists managed to isolate an immortal cancer cell line (that is, undying cells that could be grown outside of the human body) which they named [[http://en.wikipedia.org/wiki/HeLa HeLa]], after [[http://en.wikipedia.org/wiki/Henrietta_Lacks Henrietta Lacks]], an unfortunate woman who had died from the cancer. Scientists at the time were trying to isolate and grow normal human cells outside of the body but were having no luck. Within a short period of time, however, they noticed many of the normal cells suddenly being transformed into cancer cells. This puzzled scientists until they realized that the new cells were actually [=HeLa=] cells that had contaminated the normal cultures. \\
\\
[=HeLa=] cells were so durable that they were difficult to get rid of via sterilization and the tiniest bit could convert whatever normal tissue they came into contact with. [=HeLa=] cells soon spread throughout the world and even today scientists have problems dealing with [=HeLa=] contamination of their cell cultures. \\
\\
Fortunately for humanity, the [=HeLa=] cells quickly die out or result in only weak tumors when injected into a living human body (yes, there were people crazy enough to try this out). Even more fortunately for humanity, the [=HeLa=] cells ability to grow outside the human body led to it being a useful tool in the development of the Polio vaccine, in cancer research and in the testing of drugs, cosmetics and many other substances. A rare case where Grey Goo actually turned out to benefit humanity. \\
\\
Better yet, the cells are a BlackBox; ''no one in decades of research has been able to figure out why they won't die!'' At this point in time, the mass of her post-death divided cells is greater than the mass of her body at death. Something on the order of 20,000 kilograms worth. And that's in the sixty years since she passed away. \\
\\
But there is also a downside: [=HeLa=] cells benefited humanity but not Henrietta's impoverished and undereducated family; when they first heard about the immortal cells they thought scientists had her ''actual body'' being kept alive somewhere. When a woman wanted to talk to them about Henrietta for [[http://rebeccaskloot.com/the-immortal-life/ a book]], they initially hung up on her because they thought she was another scientist looking to exploit them.
** Combined with OurZombiesAreDifferent (as a mini sequel to [[ABootStompingAHumanFaceForever 10 A BOOT STOMPING]]) in the short [[http://www.amazon.com/Writings-On-Wall-Seven-Archons/dp/0988314606/ref=sr_1_2?ie=UTF8&qid=1350674384&sr=8-2&keywords=writings+on+the+wall "HeLa, HeLa"]] by Creator/JessGulbranson.
* Then there's the [[http://www.cracked.com/article_16583_the-5-scientific-experiments-most-likely-to-end-world.html theoretical threat of Strange Matter.]] The television series ''The Universe'' featured it in their 10 Ways to Destroy the Earth, and basically, ''everything on Earth melts'' like a warm ice cream sundae into non-organic goo. Sweet dreams! There are far more energetic particle collisions happening every second as subatomic matter bombards the planet and occasionally smashes into the atmosphere or the ground. So far, in the last nearly five billion years, we've somehow managed to evade such a fate. This suggests that either the energy required to produce strange matter is far larger than what the LHC can manage or the odds of such collisions producing it are so incredibly small as to be considered nearly impossible. The Earth is safe. For now!
* The scenario was first proposed by Eric Drexler. He has since dismissed it as unrealistic as it's much easier to create a bunch of tiny dumb robots that receive their instructions from a central computer (that can be disabled if it malfunctions) than it is to create tiny robots that know and are capable of doing everything they need to make copies. The dumb nanobots should serve any purpose we'd need smart nanobots for so someone would have to really be trying to create a grey goo scenario.
** There's also the thought of police nanobots designed to keep the grey goo in check, a concept called "Blue Goo".
[[/folder]]

----