->''"Arthur! Monkey out of nowhere!"''
-->-- ''WesternAnimation/TheTick''

Sometimes you have a goal in mind for your story, but you have no idea how to get there. For those times where the end justifies the means there is the ''Diabolus Ex Nihilo'' or "Devil from Nothing". The Diabolus Ex Nihilo is an enemy so foul, so horrible, and so evil that it needs no {{backstory}} or reasoning. It just appears from nowhere, does its job of shaking things up and antagonizing the heroes, and then promptly dies. The Diabolus Ex Nihilo may get a back story in the future, but it would just be an exercise in {{retcon}}ning.

This trope can often appear in [[OriginStory origin stories]] where it's more important that the characters are introduced than that they do something sensible.

See also the GiantSpaceFleaFromNowhere, which serves roughly the same function in VideoGame gameplay -- a [[BossBattle boss]] that pops up at the end of a level for no narrative reason and with no explanation, just because there's supposed to be a boss at the end of the level or the game.

Compare the GenericDoomsdayVillain, who has no clear motive for their actions other than being "evil," even if they do in fact have backstory or context. Contrast OutsideContextVillain, where the mystery behind a villain's origin, [[HiddenAgendaVillain motive]], and abilities are the source of their threat. [[RuleOfThree Consider]] InvincibleVillain, where them just showing up exemplifies how bad things can get. A Diabolus Ex Nihilo used by a writer to get out of a corner may be an example of ChandlersLaw.

Yes, this may also be a DiabolusExMachina if it succeeds in doing some damage. See also the AnthropicPrinciple where the appearance of an otherwise unexplained baddie forms the premise for the entire story. If they appear in the backstory, or disappear as quickly as they appeared, they may overlap with UnknownCharacter.

See also AssPull.
----
!!Examples

[[foldercontrol]]

[[folder: Anime & Manga ]]
* ''Anime/DigimonAdventure'': Apocalymon, the final villain, literally shows up out of nowhere in an outer space-like battlefield, and is fought and defeated within the course of two episodes. Apparently this was actually a case of ExecutiveMeddling, and there was supposed to be far more leadup to Apocalymon, as well as his relation to the Dark Masters.
** In ''[[Anime/DigimonAdventure02 02]]'', Daemon and his followers appeared randomly, had incredibly vague motivations (they want the Dark Spores... for some reason) and are defeated in a few episodes after causing some pointless mayhem. They are then quickly forgotten. The manga version is slightly better about this, in that Daemon is on Oikawa's side rather than against him.
** In ''[[Anime/DigimonFrontier Frontier]]'', after seemingly defeating [[BigBad Cherubimon]] and destroying his fortress, the heroes fight an [=IceDevimon=] who was apparently sealed inside since he was too powerful for even the Three Holy Digimon to defeat. The lack of hinting towards this and his relatively quick defeat suggests that his only purpose was to [[{{Filler}} fill up half an episode]].
* ''Anime/PrettyCureAllStars'' movies seem to have a tendency to use this trope gratuitously, due to lack of connection between individual ''Pretty Cure'' series. The latest of which, in DX3, is the entity simply known as Black Hole. It's best described as TheHeartless of every ''Pretty Cure'' villain, ever.
* Kain, the villain of the ''TenchiMuyo'' movie "Tenchi In Love".
* ''Anime/MobileSuitGundamAGE'' gets hit with this in its final episode with Zera Gins and his Vagan Gear, though his existence was hinted at earlier in the Kio arc. He shows up at the end of the final battle, when all non-mook Vagan pilots are dead, with his only motivation and lines being "destroy the Gundams." His own side calls him a soulless warrior and their strongest pilot, and it also is mentioned he's a clone of Lord Ezelcant. Then SID shows up and merges with Vagan Gear and he goes berserk causing both sides to ally to try and stop him. Then Kio destroys his Gear SID, and that's that (though Zera himself survives). As [=AGE=] was originally conceived as a licensed game by Level-5, Zera is a very direct transplant of the GiantSpaceFleaFromNowhere.
* In ''Anime/{{Hellsing}}'': The Major has no backstory and no motivation ([[spoiler: until he meets Alucard and wants to destroy him simply for being different from him]]) other than because he simply enjoys war.
* Walpurgisnacht serves as at least a partial one in PuellaMagiMadokaMagica. There's definitely some build-up to it, but it still takes a backseat to [[spoiler: the AwfulTruth behind the whole MagicalGirl system and Homura's true nature.]] In the end, its purpose in the plot is more to just show up, smash the city to pieces and [[spoiler: either kill Madoka or cause her to turn into an even more powerful witch, forcing Homura to push her own personal ResetButton and try to do the fight over again while saving her.]] Hell, if it wasn't for Homura, no one would even expect a supremely powerful witch like Walpurgisnacht to just show up and start wrecking everyone's shit.
* ''{{Series/Pokemon}}'''s episode with the evil Togepi. It's never explained why the Togepi is evil or what its motivation was.
* Subverted with ''Anime/DragonBallZ'' Cell does shows up without very no warning during the Android Saga, but explains his connection to Dr. Gero to make sure he didn't just appear of nowhere.
[[/folder]]

[[folder: Comic Books ]]
* ''{{Superman}}: The Man of Steel'' #17 introduces the most (in)famous Devil from Nothing: [[GenericDoomsdayVillain Doomsday]]. He basically emerges from the bowels of the earth, squishes a bird, and then goes on a killing spree for no good reason. He's pretty much there just to kill Superman and kick off the "Death" and "Rebirth" story arcs. Later stories revealed his origins, however.
* Darwyn Cooke's ''ComicBook/DCTheNewFrontier'' spends so much time dropping obscure DC character names that it never creates a fleshed out back story or motivation for "The Centre"--a giant living island of dinosaurs determined to cleanse the Earth and then the Solar System. Ironically, the Centre itself is from an obscure source--Dinosaur Island, a LostWorld featured in several "Weird War Tales" comics. Its existence was never previously explained, and Cooke decided to reinvent it as an alien menace.
** It seems to briefly explain its motives by possessing an {{Expy}} for Dr. Seuss, who writes it down in a story before killing himself; it reveals that it's a prehistoric entity which tired of humanity's ''noise'' and yearns to leave Earth to explore the solar system. This will require exterminating humanity for... some reason.
*** Its plan was to wipe out humanity so the Earth can heal itself from all the damages humanity has done.
* The BigBad in DC's ''FinalCrisis'' wasn't {{Darkseid}}. It was a Multiversal Vampire. This means exactly what you think it does: he eats stories. If you didn't read the ''Final Crisis: Superman Beyond'' tie-in, he seemed to come out of nowhere. Writer GrantMorrison did, however, intend for ''Superman Beyond'' to be an integral part of the story, and it is included in the trade editions of ''FinalCrisis''.
* A ''Franchise/{{Godzilla}}'' comic had Big G be sent back to the time of the dinosaurs, where he was attacked by a giant dragon... ''thing'' that was there for some reason; he manages to just barely beat it before being returned to the present.
* The feral vampire hag that turned Cassidy in ''{{Preacher}}''. She appears biting his neck, gets shot by his brother, and falls back into the swamp, never to be seen again.
* The vampire that turns Lord Andrew Bennett, title character in ''ComicBook/IVampire''. He turns up while Bennett is out riding, mesmerises him, gives a [[MotiveRant little rant]] about hating Bennett's positive outlook on life and wanting to show him the dark side and generally screw his life up, bites him, and then promptly gets staked by him. Then Andrew makes it home, filled with angst over his new condition, his wife agrees to be turned by him so that they can spend eternity together, she promptly turns evil, decides to take over the world, declares Andrew to be her enemy when he tries to talk her out of it, and flies off to begin her campaign. And there's your central plot and background set, now on with the episodic story.
* ''BrightestDay'' had [[spoiler: Black Lantern Swamp Thing]]. It's mentioned a few issues earlier that a Dark Avatar will rise, but the White Ring is vague as to exactly what our heroes will be facing, so it certainly felt like one of these.
* In GreenLantern: Rebirth, Hal Jordan's 90s FaceHeelTurn is explained and excused as a result of his possession by Parallax, a "Fear Entity" and literal GiantSpaceFleaFromNowhere. Parallax has since become the BigBad of a crossover event, [[RetCon one of the cornerstones]] of modern GL Continuity, and was depicted as the giant floating CGI head of Clancy Brown in TheMovie.
* SelfDemonstrating/TheJoker is this; his backstory was introduced [[ComicBook/TheKillingJoke much, much later]] than the character and even in there, he outright stated that's probably false. Despite that he's still managed to rack up a body count any villain worth their salt would be jealous of, and is the person regular (and super) criminals tell stories of to scare one another.
[[/folder]]

[[folder:Fan Works]]

* The ''Fanfic/PonyPOVSeries'' has the first BigBad [[spoiler:Loneliness]] who's origins have never been explained and several potential ones are offered, but nothing concrete is ever given. She just [[spoiler:shows up in Trixie's head as her EnemyWithin]]. However, this was invoked by WordOfGod, as not giving her a set origin just [[NothingIsScarier makes her that much more terrifying]] both in universe and out.

[[/folder]]

[[folder:Film]]
* The Whale Probe in ''Film/StarTrekIVTheVoyageHome'' is never given any backstory or origin. It's the quintessential BigDumbObject that exists to make [[TheKirk Jim Kirk's]] court martial more of a hero's welcome. (The probe was eventually given a back story in the book [[ExactlyWhatItSaysOnTheTin ''Probe'']].)
** [[JustifiedTrope Justified]] in Spock's exact line, "Only human arrogance would assume the message 'must be meant for Man'." One might imagine it was quite chatty with the cetacean life it was sent to contact.
* ''Film/TheFifthElement'' introduces The Great Evil, an angry, black sphere that doesn't even have a proper name let alone a motivation. But how would Bruce Willis find a cute thousand-year-old alien girl to nail without it?
* The shark from ''Film/{{Jaws}}'' has no reason to be so big, eat people, and sink boats. But thank goodness it is and does because Roy Scheider and Richard Dreyfuss are a match made in heaven. Of course, how much motivation does a ''shark'' need? Occasionally animals realize humans are pretty easy to kill and start eating them, they tend to keep doing so until they die. It helps that for most of the movie, the townspeople [[IdiotBall make little to no effort to avoid the maneating shark they know is sticking around the beach.]] The attempt to [[RetCon give it]] a more detailed backstory and motivation in the sequels is the TropeNamer for VoodooShark.
* ''Film/{{Krull}}'': The Beast appears from outer space, invades the world and randomly crashes wedding parties all in the name of being bad. While the backstory of the Cyclops indicates that the Beast has done this sort of thing on other worlds before, there's otherwise no backstory for the Beast itself explaining where it came from and why it decided to go about invading worlds.
* In ''Film/TheDarkKnight'' SelfDemonstrating/TheJoker has no StartOfDarkness, no backstory ([[MultipleChoicePast none that you'd believe, at any rate]]). He's just ''there'' at the start of the movie to wreak havoc, havoc and more havoc, [[ForTheEvulz just 'cause]], which actually serves to make him even scarier than he might be otherwise. As Alfred puts it: "Some men just want to watch the world burn."
* The ending of the American ''WesternAnimation/AstroBoy'' movie. Just as the day is saved and everyone is celebrating, a giant sun-shaped alien with tentacles that shoots lasers out of its one giant eye attacks the town. No reason, no foreshadowing, someone just shouts "Alien!" and it's there. It's probably one last ShoutOut to the Artificial Sun from one of the earlier Astro Boy series.
* Many [[OurWerewolvesAreDifferent Werewolf Movies]], such as ''Film/AnAmericanWerewolfInLondon'', ''Film/GingerSnaps'', and ''Film/{{Wolf}}'', in which the protagonists are bitten and become werewolves, do not go into very much detail, if any at all, in explaining where the original werewolf came from--or the werewolf who made them, or who made that werewolf, and so on.
* ''Film/FrankensteinConquersTheWorld '': The "International" cut climaxes in a fight between Frankenstein's Monster (in city-stomping {{kaiju}} form) and a giant octopus who suddenly shows up out of nowhere. Not only that, but it's a famous [[MisplacedWildlife Japanese Mountain Lake Octopus]], as most of the action takes place in the "Japanese Alps." Although it was filmed at the request of the American distrubutor, he apparently felt the end result was just too silly. The scene was cut from both the Japanese and American versions, but for reasons unknown, was kept in the "International" cut (English language, but for territories outside America.)
* Monster X/Keizer Ghidorah from ''Film/GodzillaFinalWars''. He just appears out of nowhere (though it's implied he was inside the meteor "Gorath" that was heading to Earth), fights Godzilla to a draw, transforms into his more-powerful form, nearly curb-stomps Godzilla to death, and then is ultimately defeated after Godzilla gets a power boost.
* The murderous robber dressed like Santa Claus from the beginning of ''Film/SilentNightDeadlyNight''.
* The killer in ''[=HellBent=]'' is given no origin or motivation, never has his name or actual appearance revealed and isn't even mentioned in the credits. Also, making a literal example of the trope, he's dressed as the devil.
* ''WesternAnimation/TheThiefAndTheCobbler:'' The Mighty One-Eye, ''and'' the entire race of [[AlwaysChaoticEvil monstrous]] [[RedRightHand One-eyed]] men he is the leader of (simply called the "One-Eyes") simply appear into the film without any kind of backstory. They want to conquer and destroy a Golden City, also without any explained motivation.
* The Leopold and Loeb-esque duo in ''FunnyGames'' give various conflicting accounts of who they are and where they came from, but they're obviously all lies. They have no backstory and no reason to exist except to serve as villains for the movie you're so sadistically viewing, YouBastard.
* In ''[[LadyAndTheTramp Lady and the Tramp]]'' there is [[YouDirtyRat a rat.]] This rat appears just ten minutes before the end of the film, [[WouldHurtAChild tries to murder a baby,]] [[DidYouJustPunchOutCthulhu fights the Tramp one-on-one, wounding him]] and [[OhCrap posthumously has the Tramp sent to the pound, where he is certain to be put down.]] He has no lines, has no known motive and is [[ForTheEvulz utterly evil throughout.]] Easily the [[TropeCodifier Trope Codifier.]]
* [[spoiler:In ''WesternAnimation/TheLegoMovie'', [[SequelHook the Duplo aliens]]]].
[[/folder]]

[[folder:Literature]]
* ''Literature/TheSilmarillion'' by Creator/JRRTolkien: [[EldritchAbomination Ungoliant]]; she is said to have "descended from the Outer Darkness, maybe, that lies in Eä beyond the walls of the World." She destroys the Two Trees and almost [[DidYouJustPunchOutCthulhu eats Morgoth]]. After breeding with lesser spiders, she just... wandered off.
-->"Some have said that she ended long ago, when in her uttermost famine she devoured herself at last."
** ''Literature/TheHistoryOfMiddleEarth'' gives more details, with Ungoliant originally written as an EldritchAbomination 'personification of primeval night' before the world was made, and later this being changed to her being a Maia and former disciple of Morgoth who grew strong enough to equal him in his long years of imprisonment. Also, Ungoliant was originally planned to re-enter the story -- Eärendil slew her in one of his adventures on the way to Valinor. It's likely this would have ended up in ''TheSilmarillion'' if Tolkien had ever finished that part of the story.
* With the exceptions of Blaine the Mono and Andy the Messenger Robot (Many Other Functions!), pretty much every robot in ''Franchise/TheDarkTower''. They show up, kill, maim, or psionically alter someone, then are either destroyed or returned to hibernation.
* "The One" from ''Literature/{{Animorphs}}.'' It is a literary GiantSpaceFleaFromNowhere, introduced in the very last book after the [[PuppeteerParasite Yeerks]] are defeated. There is no explanation of where it came from or what it wants, it merely becomes the remaining Yeerks' [[AGodAmI new god]], [[TheAssimilator assimilates]] Ax, shapeshifts to a bunch of random things to freak the heroes out and gets its spaceship rammed. Creator/KAApplegate's [[WordOfGod comments]] seem to indicate that she just wanted the good guys to get screwed by a new war and created a DiabolusExMachina to let them go out in a blaze of glory.
** Whatever it was that sent Jake to a BadFuture, as some kind of test, in ''The Familiar'', the definitive BizarroEpisode of the series.
* In the ''Literature/WarriorCats'' series, the BigBad Tigerstar had nine lives at the beginning of the (then) final book, ''The Darkest Hour''. In order to avoid making him seem like a pathetic weakling, the authors had a random cat called Scourge show up, kill Tigerstar all nine times, kill ''the protagonist'', Firestar, and take over the Clans. And then Scourge died.
* The Lady of the Green Kirtle in ''Literature/TheSilverChair'' has absolutely zero backstory whatsoever. We know she's a "Northern Witch," and she might be somehow connected with the infamous [[Literature/TheLionTheWitchAndTheWardrobe White Witch]]...but that's about it.
* Swedish writer Simona Ahrnstedt gives us Carl-Jan Rosenschiöld in her debut novel ''Literature/{{Overenskommelser}}''. To be fair, this novel has three villains (because one creep obviously wasn't enough), whose misogyny is disgusting even by the standards of the time in which they live (the 1880s). But the other two are at least given backstories, which can somewhat explain how they ended up being that way. But with Rosenschiöld, the guy is just there to be evil! He's a sadistic serial abuser of women, who only wishes to marry female protagonist Beatrice (who's like forty years younger than him) because he wants a virgin. We do get to see him die, but not until after he has [[spoiler: brutally raped and almost killed Beatrice on their wedding night.]] Only after his death are we given some backstory: Rosenschiöld has murdered one previous wife and driven another previous wife into suicide. But we're never told how he could become so evil.
[[/folder]]

[[folder: Live Action TV ]]
* ''Series/StarTrekTheNextGeneration'''s pilot episode introduces "Q", a god like entity that begins harassing the crew seemingly for the sake of it. He simply appears on the bridge and creates unnecessary drama. While he eventually becomes a beloved character by the end of the series, he was unimportant to the plot of the pilot. WordOfGod says that the pilot was originally going to be one episode, but ExecutiveMeddling forced it to become a two part episode. So Q was made up to fill the extra hour.
* ''Series/StarTrekTheOriginalSeries'' had the Doomsday Machine from the episode of the same name, a giant weapon that flies through space eating everything it comes in contact with, up to and including entire planets. Spock believes it came from another galaxy, and Kirk theorizes it may have been built as a form of MutuallyAssuredDestruction in a war, intended as a bluff or deterrent but ultimately used, however the true origins and purpose of the machine are never revealed.
** The ExpandedUniverse novel "Vendetta" by PeterDavid reveals that it was designed to destroy the Borg.
* The enemy from the ''Series/DoctorWho'' episode "[[Recap/{{Doctor Who NSS 4 E 10 Midnight}} Midnight]]" -- we never see its true form, or learn its name. It just appears out of nowhere, possesses Sky, places the Doctor and everyone with him in grave danger, [[spoiler:and is eventually defeated - but certainly not killed - by a random bystander, as it's incapacitated the Doctor]]. Considering how often the Doctor exhibits an encyclopedic knowledge of... everything... throughout his adventures, many count the episode as one of the eeriest in all of ''Doctor Who'', to the point of ThatOneCase.
* In ''Series/KamenRiderDecade: All Riders vs. Great Shocker'', there's King Dark, the Big Bad of ''Series/KamenRiderX'', who only rises after all the other villains are killed. It was never hinted anywhere in the movie that he would even appear at all. Since there is already a personification of the Great Leader, recurring Bigger Bad of the Showa era in [[spoiler:the eponymous Decade]], it means that there are two Great Leaders running amuck. He was probably just included to give an excuse to use the giant ''Film/KamenRiderJ'' (the movie did say ''All Riders'').
** And then [[spoiler: [[Film/KamenRiderZO Doras]] shows up in Decade's GrandFinale after dealing with both [[VillainProtagonist Tsukasa]] ''and'' [[TheRemnant Super Shocker]] almost out of nowhere.]]
* The creators of ''Series/{{Merlin}}'' promised in an interview that the end of season four would end with an intriguing CliffHanger in which a previously seen "evil" character would reappear. Most fans bet their money on Mordred. However, it turned out to be something completely random. In an early season four episode Merlin discovers a dragon's egg, hatches it, and calls the baby dragon Aithusa, said to be a symbol of the forthcoming Golden Age of Camelot. The audience was given absolutely no reason to believe that Aithusa was anything but a harmless baby dragon, who is not seen or mentioned until the end of season four, where it appears in the forest to heal an injured Morgana for no apparent reason and fly off again.
* In BuffyTheVampireSlayer, the First Evil is the CosmicHorror personification of evil. It wants to make people hurt and sin because, well, it's ''evil''. There's not really much else to say about it, aside from what's on the tin.
[[/folder]]

[[folder:Mythology]]
* In Hesiod's ''Literature/{{Theogony}}''--an early TropeCodifier of GreekMythology--Typhon is one of these. He shows up out of nowhere to wreck havoc after the Olympians win their war against the Titans and Giants. Zeus Curb Stomps him and the world is finally at peace. Some later retellings either edit this bit out for being too random or write the battle as a more grandiose affair.
** Various tellings of the story change a bit of that; Typhon is described as a child of Gaia and Tartarus, set against Zeus by Gaia when she realized his rule wouldn't be much better than his father's. The battle was less a curb stomp, with Typhon having the edge early on (ripping out Zues' tendons) before being defeated by having a mountain dropped on him.
[[/folder]]

[[folder: Tabletop Games]]
* ''TabletopGame/LegendOfTheFiveRings''' notorious Hidden Emperor story arc featured Goju Adorai. He appeared halfway through the arc which continued to focus on other evil characters such as the Kolat, Onnotangu, and the possessed Toturi. Adorai finally shows up during the climatic battle at Oblivion's Gate as the leader of the Lying Darkness's forces where he is defeated with virtually no information ever given about his back story or motivations.
** Arguably, the [[EldritchAbomination Lying Darkness]] as a whole.
* People have spent years thinking of ever-sillier ways to defeat ''TabletopGame/DungeonsAndDragons''' Tarrasque, but what the hell ''is'' it?
** TheOtherWiki has [[http://en.wikipedia.org/wiki/Tarasque a page on the original legend]].
** [[{{TableTopGame/Spelljammer}} One source]] implied that Tarrasques (there exists more than one, once you travel between the Spheres) are docile lizard-like lithovores that react poorly to being away from their native planet.
** Pathfinder explains it as the spawn and herald of the settings main evil god.
* By definition, any RPG modeled after the CosmicHorrorStory will tend to feature these.[[/folder]]

[[folder: Theater]]
* Don John in MuchAdoAboutNothing. It would have taken Will all of 2 minutes to write one line about him being angry at Claudio for some past slight, but instead he wrote the character to be evil for evil's sake. Stupid bard.
[[/folder]]

[[folder: Video Games ]]
* Jenova in ''VideoGame/FinalFantasyVII'' appears from the sky two thousand years ago and murders most of the planet's population. After being dismembered and frozen she is revived in modern times and starts all over again. No motive or origin is ever given.
** Sephiroth hints that the cycle of parasitic destruction is Jenova's true purpose: it crashes into a planet, sucks out the Lifestream energy, and then leaves to crash into another planet. However, it's very vague at best. Sephiroth's goals may be his own, rather than an extension of Jenova's. However, in ''Advent Children'' Sephiroth ''does'' explicitly claim that he shall sail the Cosmos to find another planet to find a shining future, like his mother once did. So maybe he really ''is'' following Jenova's Goal after all. As usual of the trope, the explanation comes 10 years after the game and from a different writing team.
** In ''DirgeOfCerberus'', Omega Weapon's purpose is similar to Jenova's: to take the life energy of the planet and find a new planet when planet-shattering catastrophes happen.
* Necron in ''VideoGame/FinalFantasyIX''. The last boss of the game, it is basically the god of death, and where he comes from, how you get to the area he resides in, or why he wants to kill you all is not even close to explained.
* Sulphur from ''PhantomBrave'' is this monstrous demon thingy that wants to kill everyone. Nobody knows why, nobody asks why.
* ''VideoGame/ChronoTrigger'': Jenova's grandpappy, Lavos: it [[spoiler: [[GainaxEnding (he?)]]]] falls from the sky in the distant past, causing the equivalent of the [[PhlebotinumKilledTheDinosaurs Creataceous extinction]]. [[PlanetaryParasite Millions of years nourishing out of the planet's core later]], it (after an initial firestorm) emerges and [[TheEndOfTheWorldAsWeKnowIt proceeds to wreck the place]]. [[spoiler: And it was not the first time: he had done it before when the premier magicians in the world [[EvilIsNotAToy tried to use it for fuel.]]]]
** And then there's ''VideoGame/ChronoCross'', where the final boss [[spoiler: is yet again Lavos, who exists in a non reality unplace of infinite nothing never where the countless versions of people are erased over.]] Oh, and then he [[spoiler: decides to eat all of time because of Crono's actions in the first game.]]
* The Dark Star in ''[[VideoGame/MarioAndLuigiBowsersInsideStory Mario & Luigi: Bowser's Inside Story]]''--someone accidentally dug it up one day, realized that whatever the hell it was, it was ''bad news'', and immediately called upon the royal family to seal it away. [[BigBad Fawful]] thinks that it might be useful. [[spoiler:[[EvilIsNotAToy He is dead wrong]].]]
* The titular mothership of the ''VideoGame/{{Fallout 3}}'' add-on ''Mothership Zeta'' deserves mention. Without any previous foreshadowing, the [[PlayerCharacter Lone Wanderer]] is abducted by the aliens and must spend the next several hours (days, in game time) fighting his way through the mothership just to get home. At which point, the entire experience is never mentioned again. What exactly the aliens were ''doing'' with all the people they've been abducting over the past thousand years or so is left vague at best.
* [[spoiler:The Aurum]] in ''VideoGame/KidIcarusUprising'' are explicitly stated to "come from and return to nothing". [[spoiler:They are a strange robotic alien HiveMind that come from nowhere and become the main threat for Chapters 15-17, and force Palutena, Hades, and Viridi to form an EnemyMine.]]
* In the Legend of Skyloft told in ''VideoGame/TheLegendOfZeldaSkywardSword''[='=]s introductory sequence, it is told that one day, demons suddenly rose from the ground out of nowhere and started killing everyone, forcing the Goddess Hylia to raise a human settlement above the clouds to keep them safe. The plot during the game proper deals is caused by the remnants of the demonic forces, but the game's plot doesn't touch on where they came from.
* ''VideoGame/BatenKaitos Origins'' introduces [[HumanoidAbomination Wiseman]], who fits this trope to a T.
* "Bridge of Sighs", the mission 14 of ''VideoGame/{{Homeworld}}'', has your fleet opening a path for your ancestral homeworld. You jump in hyperspace to reach it... And then we have "Chapel Perilous, in which, for no explained reason, you're pulled out of hyperspace halfway from there, with the [[TheEmpire Taiidan]] [[ColonyDrop launching an asteroid at the Mothership]] while a huge fleet attacks you.
[[/folder]]

[[folder: Web Comics ]]
* Parodied in ''Webcomic/{{Adventurers}}''--possibly even a direct parody of [[VideoGame/FinalFantasyIX Necron]]--when, after finally defeating the distinctly non-Space-Flea FinalBoss and fleeing his collapsing lair, the party is suddenly faced with [[http://www.adventurers-comic.com/d/20060103.html Necrevil]], "the embodiment of evil ''itself''!"... and they just keep running.
** [[http://www.adventurers-comic.com/d/0170.html Eternion on his first appearance]] is also an abrupt GiantSpaceFleaFromNowhere, but he becomes a recurring villain and arguably has more of an impact on the plot than the BigBad himself.
** While he's decidedly more human than most examples of this trope, [[http://www.adventurers-comic.com/d/0295.html this guy]] still qualifies by dint of location.
* Morthol Dryax in ''Webcomic/ProblemSleuth'', who [[http://www.mspaintadventures.com/?s=4&p=000916 pops up]], is soundly defeated 22 pages later, and isn't mentioned anywhere else. [[EldritchAbomination Fluthlu]] counts as one too, and [[http://www.mspaintadventures.com/?s=4&p=000950 appears shortly after beating Morthol Dryax.]] It's also never mentioned again in the series, apart from a MythologyGag or two in ''Webcomic/{{Homestuck}}''.
* ''Webcomic/{{Homestuck}}'' kind of plays with this trope. The [[AnachronicOrder nonlinear]] nature of the story means that for the reader it doesn't come out of nowhere, but from the perspective of most of the trolls [[spoiler: Bec Noir was this, suddenly appearing shortly after they defeated their FinalBoss.]]
* The [[http://bobadventures.comicgenesis.com/d/20070127.html Rogue Canadian Scientists]] in ''TheInexplicableAdventuresOfBob'' were introduced this way, as a joke threat from nowhere that was defeated in just a few panels. They return as a more serious threat about four years later.
[[/folder]]

[[folder: Western Animation ]]
* ''WesternAnimation/TeenTitans''
** Slade, whose backstory and motives were never revealed, despite the fact that he was the BigBad for the first two seasons, the DragonWithAnAgenda in the fourth, and had cameos throughout. The heroes, especially Robin, speculate as to who he is, but nothing concrete is ever reached.
** Also, the [[MonsterOfTheWeek Monsters of the Week]] from the episodes "Stranded" and "Things Change" similarly come out of nowhere and, though the characters wonder out loud what they are, are never given even a vague explanation.
** Also Red X has no explanation or origin for his appearance, and no back story. He just appears out of nowhere and makes trouble for everone. Beast Boy tries to speculate, but Raven says it could be anyone and no one else bothers speculating.
* Dr. Claw in ''WesternAnimation/InspectorGadget'' is a faceless enemy that is constantly plotting against the titular hero. His organization seems to have no other purpose than to "Get Gadget". Claw's face was not even revealed until nearly twenty years after the show's run ended. Except on a toy.
* ''WesternAnimation/TransformersTheMovie'' features BigBad Unicron who drifts out of the vastness of space and starts eating things and making bargains with Decepticons. Though he appeared from the vacuum, he certainly didn't vanish afterward though.
** Further incarnations were slightly more careful with this. Armada hinted he was in the background for a while, Energon followed as a sequel, and WesternAnimation/TransformersPrime dropped hints about him every now and then before he appeared for real.
* ''WesternAnimation/ThunderCats'': In the series finale, after Lion-O fights an epic final battle against his ArchEnemy Mumm-Ra, the Ancient Spirits of Evil randomly throw "their champion," a giant warrior named Pyron, at Lion-O just to fill up the last couple of minutes or so of the episode.
* Although not many of the villains in ''WesternAnimation/ThePowerpuffGirls'' have elaborate origins, the [[{{Nanomachines}} nanobots]] in "Nano of the North" seem especially noticeable in this regard. They're a swarm of microscopic robots that come out of a cloud that forms over Townsville but nothing else surrounding it, start devouring all the carbon to make more of themselves, and demonstrate some kind of group intelligence in the way the cloud changed to focus the forces onto the Powerpuff Girls. Although they're all destroyed by the end of the episode, no clue is given as to their origin or why they were targeting Townsville specifically, and indeed no one even ''asks''.
** The evil alien force from "Forced Kin" qualify as well.
* The Loc-Nar from ''WesternAnimation/HeavyMetal'' is never given a backstory, but it's the embodiment of Pure Evil that drives all the vignettes in the movie.
* In the {{Backstory}} of Equestria as told in "Hearth's Warming Eve" in ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', the Windigos were these. They were said to be creatures that feed on ThePowerOfHate, but they came out of nowhere and had absolutely no explanation for what they planned to do with the winter they were causing, but they forced the three races of pony to band together, since they were able to create a beacon of friendship-powered fire to burn them away.
* In ''WesternAnimation/RegularShow'' Mordecai and Rigby are vying for a chair and bet on it in rock-paper-scissors. After being stuck in tie for 100 times, a monster from out of nowhere comes to eat the chair, they were able to make it go away by breaking the tie.
** This is actually the formula many of their episodes run by. The characters start off doing something fairly mundane, like going on a date or buying fast food, then all of a sudden, the fantastic [[MonsterOfTheWeek enemy of the week]] pops up to give the characters a new conflict.
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