Universal-scale Physical Annihilation. Everything that has ever been observed by anyone, anywhere. Eradicated. Or at the very least, not organized into galaxies, stars, and planets anymore.

It is the end of all things. Unless there are [[AnotherDimension other dimensions]]; those are safe.

----
!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* The eventual result of Getter Rays use in ''GetterRobo'', caused by the energy going out of control, is the end of the entire universe. Some of the AU series like ''New Getter Robo'' and ''Armageddon'' suggest that the consequences could go ''beyond'' that, into other universes, as well.
* ''Anime/TengenToppaGurrenLagann'''s Spiral Energy is described by [[spoiler: the Antispiral as, if left unchecked, able to cause the entire universe to collapse into a Black Hole, ending the universe in the Spiral Nemesis]].
** [[spoiler: The Antispiral's pocket universe actually IS destroyed when the Super Tengen Toppa Giga Drill Breaker meets the Anti-Spiral Giga Drill Breaker. Good thing it was almost completely empty.]]
* In ''{{Slayers}}'', the destruction of the entire universe is the least you can expect if the [[DangerousForbiddenTechnique Giga Slave]] goes out of control... barring a DeusExMachina, anyway.
* What the Data Overmind, the Agency, and Mikuru's boss want to prevent indirectly by not allowing SuzumiyaHaruhi to discover her powers.
** In an unsettling twist, it's implied that [[spoiler:the Class X-4 has already happened at least once, about three years ago, and that's why Mikuru's organization was suddenly unable to time-travel past that point. No one else noticed anything amiss, since their memories were generated from scratch along with everything else in the new universe.]]
*** Rather uncomfortably, [[spoiler: this happened around the time when a young Haruhi went to a sporting event and saw enough people in one place that it made her feel small and insignificant. ''That'' is all it takes for Haruhi to rewrite the universe. No wonder everyone is worried.]]
* ''Anime/TransformersCybertron'' has Unicron's death leaving a universe-threatening black hole behind.
** Before that, though, he had already eaten a fair number of universes, bit by bit. That's what his {{planet eat|er}}ing ultimately culminates into. However, the information is AllThereInTheManual.
* Kyubey's goal in ''Anime/PuellaMagiMadokaMagica'' is to prevent the heat death of the universe through the breaking of the Second Law of Thermodynamics through magic. Being an emotionless StarfishAlien that doesn't care one whit about humans, its way of pursuing this goal -- [[spoiler:creating a cycle where he harvests emotional energy to combat entropy through turning girls into Magical Girls who eventually turn into {{Eldritch Abomination}}s that prey upon humanity and that other Magical Girls have to fight]] -- is rather suspect, to say the very least, particularly since [[spoiler:it doesn't care if the world and humanity cease to exist, so long as the universe itself survives]].
** By means of a complete fluke, Kyubey gets what it wants... [[spoiler:By making Madoka a goddess.]] However, in so doing, Kyubey also shoots itself in the foot. [[spoiler:In her wish to become a goddess, she also takes out the entire Magical Girls-to-Witches system and destroys the universe as they known it as a result. This is rectified only by her being a goddess and re-writing the universe after its destruction. Her new world isn't perfect. Demons apparently threaten the world but also give Kyubey a new source of energy to prevent the heat death of the universe with, and the means to keep creating magical girls (bar one).]]
* The forfeit for losing the "game" in ''{{Bokurano}}'' is this: complete destruction of the loser's universe. Of course, the reward for the pilot of the winning team is instant death.
[[/folder]]

[[folder:Comic Books]]
* Although ''ComicBook/CountdownToFinalCrisis'' is largely CanonDiscontinuity now, Universe-51 of the current 52 universes of DC was destroyed. Twice. The first time was a battle between Superman-Prime and Monarch (aka CaptainAtom being evil again). Prime ripped open Monarch's suit which released all of the energy Monarch had collected (similar to the movie ''The One'' Monarch had killed and absorbed all of his multiversal duplicates), which destroyed '''the entire universe''', save for its Monitor and one single plant. The second time was much more low key, a highly mutative virus affected everyone on Earth and was spread throughout the universe by Hal Jordan, initially a Class 3b or a 4. But at the beginning of ''FinalCrisis'' the Monitors wipe all life from it, making it devoid of life.
* Hal Jordan as Parallax was responsible for this in ''ZeroHour: Crisis In Time'' when he erased all of existence save for a few individuals that he spared just so he could remake the universe as he wanted it.
* [[BlackestNight Nekron's plan]] is a universe-scale Class 6: by killing the Entity, the result would be a simultaneous death of every living thing in the universe.
* Marvel's What If #32 featured a variation of Avengers #177, where energy being Michael Korvac by steps absorbed all life from earth into himself...including all superhumans and the visiting Celestials. Conquering Marvel's pantheon of cosmic omni-beings, including The Stranger, The Inbetweener, et al, in the end he found no satisfaction in his accomplishments. Therefore, in one of comics' most horrific moments he produced Galactus' Ultimate Nullifier device and used it to to disintegrate himself and the entire universe!
* In ''ComicBook/TheMetabarons'', at some point in its storyline our universe gets invaded from a parallel universe. A member of the eponymous noble family saves our universe by destroying the other universe [[spoiler:with his PsychicPowers]].
* The supervillain Annihilus from {{Marvel}} is a good example; he's so obsessed with living forever he plans to exterminate all other life in the universe, just so there's nothing that can threaten him.
* During the original US Marvel ''ComicBook/TheTransformers'' comics, Primus related the story that Unicron predated the current universe, and had actually ''eaten'' the previous one. After the Big Bang, he woke up and started over.
* The alternate-reality ''MarvelZombies 2''. A grouping of superheroes-turned-zombies, all charged with cosmic powers, fly into space and [[spoiler: with the exception of a small group of humans, eats the population of the entire known universe. Or as Hank Pym says, "I can't believe we ate the whole thing."]]
[[/folder]]

[[folder:Fan Works]]
* In ''FanFic/GenderConfusion'', the collapse of the dimension is the encroaching doom for the majority of the story, whether it's in focus or not. [[spoiler:Very, ''very'' narrowly avoided, being replaced by a continental Class 4 instead.]]
* Creation has undergone this is ''FanFic/AlchemicalSolutions''. It may have even been a Class X-5, but Autochthon has been confirmed to have survived.
[[/folder]]

[[folder:Films]]
* The worst-case scenario of a time paradox in the ''Film/BackToTheFuture'' universe is a Class X-4 unraveling of the space-time continuum.
** [[MadScientist Doc]] surmises that it may actually be limited to an X-3, only destroying their own galaxy. Marty is not comforted by the thought.
*** Which makes it a good thing that counterparts usually faint.
* The aliens in ''Film/Plan9FromOuterSpace'' claim that they only want to destroy humanity in order to prevent humanity from developing Solabonite, a weapon that could destroy the entire universe. At the end of the movie the aliens are defeated. Meaning that humanity will go on to develop Solabonite and destroy the entire universe. "You see? All you of Earth are idiots!"
* ''Film/{{Ghostbusters}}'': Don't cross the streams. Just don't.
[[/folder]]

[[folder:Gamebooks]]
* The Heart of Volent in ''Literature/HeartOfIce'' will give any human who touches it [[AGodAmI absolute power over the world]]. [[spoiler: Sort of. Using the Heart will utterly destroy the entire universe, and replace it with one of the user's making and with them as an omnipotent deity.]]
[[/folder]]

[[folder:Literature]]
* OlderThanTelevision: William Hope Hodgeson's 1908 ''Literature/TheHouseOnTheBorderland'' depicts the demise of Earth, the solar system, and possibly the universe, all consumed by Chaos and an all-devouring Green Sun.
* ''Franchise/TheHitchhikersGuideToTheGalaxy'':
** In ''Literature/LifeTheUniverseAndEverything'', the Silastic Armorfiends have commissioned Hactar to create a superweapon that will connect to the heart of every star in the universe and cause them to go supernova, effectively killing everything in existence. Hactar initially has second thoughts about it.
*** [[OmnicidalManiac The Krikkits]] want to destroy everything in existence except their solar system, and came quite close to at least destroying the galaxy. [[spoiler: Hactar manipulated them into trying this, so he could give them the Supernova Bomb and fulfill the function given to him by the Armorfiends]].
** Casually mentioned in ''Literature/TheRestaurantAtTheEndOfTheUniverse'' and ''Fit the Seventh'' of [[Radio/TheHitchhikersGuideToTheGalaxy the radio series]]:
--->Narrator: There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.
* StephenBaxter:
** In the ''XeeleeSequence'' [[spoiler: the Photino Birds are altering the structure of the universe to make it more hospitable to Dark Matter life forms like themselves, in a process which would render the universe uninhabitable to Baryonic life]].
** In ''Literature/ManifoldTime'', [[spoiler:the Blue Children instigate a Vacuum Collapse incident, causing the fabric of space to collapse into a new energy state within a bubble expanding at lightspeed.]]
* Creator/GregEgan, ''Literature/SchildsLadder'': A science experiment gone wrong creates a sphere of complete annihilation expanding at half the speed of light. The sphere actually [[spoiler:contains an entirely new universe filled with far richer and more vibrant life than ours]], but that's small comfort to those in the universe being destroyed. [[spoiler:Except for the sufficiently advanced posthuman.]]
* In Creator/FrederikPohl's ''Literature/HeecheeSaga'', the Foe are energy beings who are [[spoiler: reversing the expansion of the universe with the intention of surviving through the Big Crunch so they can reshape the subsequent rebounding universe into one with more suitable physics for pure energy beings.]] They'll inflict Class 3s along the way, to make sure no one can interfere with the process.
* The climax of Creator/CharlesStross's ''[[TheLaundrySeries The Atrocity Archives]]'' is set on an [[AlternateHistory alternate world]] where [[spoiler: the [[{{Ghostapo}} top-secret Nazi necromancy project]] used the souls of those murdered in the Holocaust to summon an [[EldritchAbomination Infovore]], creature of a universe that succumbed to Entropic Heat Death aeons ago and use it as a weapon against the Allies, wiping out all life on Earth except for the Nazis. Unfortunately for them, the Nazis didn't realize that they weren't in control of the Infovore until it was much, ''much'' too late - and after it ate the Nazis as well, it began consuming all the energy of the rest of the universe, causing it to undergo Heat Death as well. Eventually it began sucking energy directly from the Space-Time Continuum, causing the universe to begin to collapse. Now it wants to escape to our universe]].
* The [[{{Satan}} Lone Power]] in the ''YoungWizards'' series causes a star to go nova in an attempt to kill just ''two'' people. That's the least of their worries. What about the Pullulus - the rapid dark-matter expansion that caused the universe to literally tear itself apart at the seams, made people more violent, and, oh yeah, cause wizardy to stop working? That one got closer to ApocalypseWow towards the end.
* In the deterministic cosmos of KurtVonnegut's ''SlaughterhouseFive'', Billy Pilgrim learns that in the distant future, a Tralfamadorian will invent a spaceship fuel that when ignited will accidentally destroy the universe. Since it's fated to happen, this bothers no one. So it goes.
* The possibility of accidentally doing this to ourselves is the focus of Creator/JoeHaldeman's ''Forever Peace''. A massive supercollider with a diameter the same as one of Jupiter's moons (being built along said moon's equator) won't just simulate conditions within nanoseconds of the Big Bang -- it'll ''set off'' another Big Bang. Because we now have the ability to annihilate not just ourselves, but possibly the entire universe, the main characters consider themselves under an ethical obligation to explore and perhaps force peace upon humanity through some AppliedPhlebotinum, because ''somebody's'' going to push that button someday. In fact, [[{{Cult}} somebody]] wants to.
* In Creator/AlanDeanFoster[='=]s ''HumanxCommonwealth'' series, the galaxy (and many before it, by all accounts) is threatened by a [[EldritchAbomination region of ultimate emptiness]] that annihilates all matter and energy that it comes into contact with. It's somehow sentient and malevolent... and it's heading our way. While you wrap your mind around that, consider that [[spoiler:the LostSuperweapon that the [[{{Precursors}} Xunca]] created to counter it uses the combined energy of several million galaxies to rip holes in spacetime.]] And even before all this came into the picture, ''The End of the Matter'' featured a massive, rogue, solar system-devouring black hole (X-2 classification) -- and a LostSuperweapon to counter ''that''.
* The Convergence from ''{{Pendragon}}'' might be this. Due to the massive amounts of [[MindScrew mindfuckery]] involved, it's hard to say for certain, but this seems the most likely scenario from what information we're given.
* ''[[Literature/CitiesInFlight The Triumph of Time]]'' (UK title: ''A Clash of Cymbals'') by Creator/JamesBlish ends with the destruction of the [[spoiler: entire ''Universe''. However the Multiverse endures, as everyone is given the opportunity to shape a new universe themselves. The main character believes so much in free will he refuses to give any shape to his own new universe and blows himself up, thus creating a totally random universe.]]
* Creator/PhilipJoseFarmer's ''Dark Is The Sun'' takes place on Earth billions of years in the future. At one point, humankind's civilization was so advanced that they found a way to move the Earth to avoid being burned away by the Sun when it eventually expanded into a Red Giant star. When the book starts, civilization has reverted to a primitive level, and eventually the group of protagonists discover that the universe itself is coming to an end via the Big Crunch. Their new goal is to find a way to enter another universe to avoid being crushed into a singularity along with everything else in their universe.
* This rank of apocalypse is subverted in Literature/{{Discworld}}, where the universe is ''continuously'' being destroyed and recreated non-stop by the AnthropomorphicPersonification of Time. Also once by a pissed-off postal worker.
* In the two prequel novels to the Literature/LiadenUniverse series the enemies are so powerful they [[spoiler:destroy the entire universe the main characters are from. The only way they escape is fleeing to a different universe]].
* Iar Elterrus features this with the Executioners in ''Belief of the Outcasts''. Said Executioners wander from universe to universe looking for certain symptoms or events. While some universes are healthy and some require intervention, an Executioner might encounter an universe damaged and corrupted beyond salvaging. The Executioner's duty in this case is called Judgement: wipe out all life, all afterlife and any spiritual residue of the universe and maybe some neighboring corrupted ones as well, placing their job between X-4 and X-5. While not a happy job by any means, the Executioners would better not slack off - any universe left for itself in spite of fulfilling the criteria for Judgement will spread the corruption and slowly destroy other universes, leading to a potential merging of Class X-4 and Class X-5 events into a single Class Z event.
* Happens at the end of the LeftBehind book ''Kingdom Come'', as [[EarthShatteringKaboom the old earth passes away]] and the "new heavens and new earth" is created, in accordance to [[Literature/TheBible the Word of God]].
* Justified in Creator/ShelSilverstein's poem "Hungry Mungry", when Mungry starts out by eating his parents, and then proceeds to go all the way up to Class X-4 by eating up the United States, the world, and finally the universe!
* ''Literature/LabyrinthsOfEcho'' by Max Frei:
** While Khumgat, the Corridor Between Worlds, is likely a fixture, worlds themselves are not. They may be born or created and may as well die with the creator.
** Part of the JustBeforeTheEnd setting in the Kingdom of Echo where AuthorAvatar Max travels to. The world is in danger of being destroyed by magic overuse. While an AncientTradition organization is working to prevent it, most of the members are capable to move to AnotherDimension should they fail.
** Loyso Pondokhva's agenda was initiating an X-4 to X-5 event to grab the world's power as said world ended.
** ''Return of Ugurbado'': The eponymous Ugurbado has a unique [[PowerParasite relation with his killers,]] [[ResurrectiveImmortality coming back to life]] with a copy of their powers. Juffin Khalli notes that if Ugurbado was to obtain [[RealityWarper Arbiter]] powers in this fashion, he and fellow True Magic users would start looking for a new world, condemning Echo.
** ''Shavankhola's Gift'': an ancient mage unwillingly created thousands of worlds where their artificial inhabitants are locked in AndIMustScream state. Hence two mages aware of those Dead Illusion Worlds are actively working on achieving an X-4 to X-5 in every one of those worlds as a form of MercyKill. [[spoiler: Max calls Loyso Pondokhva to their aid, giving him a job to match his life's dream.]]
[[/folder]]

[[folder:Live-Action TV]]
* ''Series/DoctorWho'': The Master nearly does this in [[Recap/DoctorWhoS18E7Logopolis Logopolis]]. The rest is only saved by a HeroicSacrifice.
** In the episode ''Utopia'', the Doctor travels 100 trillion years into the future to the end of the ''universe'', though it's natural entropy.
** The [[spoiler: Time Lords]] attempt this (possibly a Class X5 or Z) in ''The End of Time'', [[spoiler: from their perspective, a last ditch attempt to survive the Time War, during its last days]].
** In the Eleventh Doctor's first season, he spends the whole series figuring out why Time itself had become cracked and erasing people and events from history, eventually discovering that the cracks are from an explosion caused by someone or something destroying his TARDIS. Unfortunately, he gets trapped inside [[TailorMadePrison the Pandorica]] before he can prevent the explosion from happening and thrown into a parallel universe where stars are a myth, Earth is the sole planet in existence and reality itself slowly winding itself down. He later hits upon a plan to restore the universe by using the Pandorica itself, which was designed to preserve ''everything'' inside of it and thus captured an imprint of the universe ''before'' the explosion, allowing the Doctor fly it into the TARDIS explosion and reboot the universe, but trapping himself on the other side and [[{{RetGone}} removing himself]] from it. Turns out he was counting on the fact that Amy's long term exposure to living in a house with a Time Crack spilling into it would allow her to remember just enough to pull him back into the universe.
* ''Series/{{Farscape}}: The Peacekeeper Wars'' - At the climax of the show, John Crichton unleashes a wormhole weapon which will "eat the universe" unless the warring sides make nice. Having spent four years desperately warning people that it's not a good idea to have them he finally builds one and goes on to prove his point by creating a weapon that swallows a planet, two entire battlefleets and doubles in size every fifteen seconds or so, and will never, ever stop growing. Even MagnificentBastard, and sometimes OmnicidalManiac (towards the Scarrans at least) Scorpius admits that this weapon is madness.
* ''{{Lexx}}'' had [[FromNobodyToNightmare Mantrid]] destroy the Light Universe by converting it all into self-replicating drones, then sent every drone into a very confined area, accidentally causing the Big Crunch.
* The Magog of ''Series/{{Andromeda}} '''eat galaxies'''''.
* One episode of ''Series/StarTrekDeepSpaceNine'' involved an accident that threatened to overwrite the universe.
** Which was then dumped in the Gamma Quadrant and forgotten. [[{{Headscratchers}} You'd think]] it would've troubled the Dominion at some point...
* In ''Series/CharlieJade'', a side-effect of [[MegaCorp Vexcor]]'s plan to [[PlanetLooters steal water from a parallel Earth]] would have been the destruction of a third universe (ours, incidentally).
[[/folder]]

[[folder:Tabletop Games]]
* This is what the werewolves of ''TabletopGame/WerewolfTheApocalypse'' were fighting to stop -- the transformation of Earth and all realms beyond into a breeding ground for the Wyrm, a being of universal entropy and decay.
* ''TabletopGame/MageTheAscension'' has the Nephandi trying to destroy everything (the scope of "everything" is fuzzy, but at least includes all of Earth). For some, that's the end goal, while others want some monster or another to come in and replace it.
** In the fourth doomsday scenario for Mage, the Nephandi actually win. However, they don't destroy the universe, but merely make it a real crapsack.
* The various villains (and heroes) of ''{{Exalted}}'' walk up and down the entire [[ApocalypseHow index]], but the most serious ones end up here. The [[SealedEvilInACan Neverborn]] (murdered creators of the universe) want to feed all reality to the Void to end their own suffering after [[TooDumbToLive some idiot woke them up]]; the [[FairFolk Raksha]] want to rip Creation to shreds and return everything to the MindScrew filled choas of the Wyld; and some of the [[OurDemonsAreDifferent Yozi]] (the creators of the universe who were simply imprisoned inside the mutilated body of their king) are crazy enough to see this as an acceptable outcome as long as everything else gets screwed over with them.
** The Primordials (what the Neverborn and the Yozis were) were worlds unto themselves. When a Primordial is killed and become a Neverborn, that world experience this grade of ApocalypseHow.
** Also, at the heart of the Imperial Manse lies the cutely named Basilica of Final Victory, which is a system whose purpose is to ''annihilate the whole universe except the Imperial Manse''. The idea is that if the world is ever overwhelmed by its enemies, the best option will be to sacrifice it to destroy them (the "final victory"), and then to rebuild it from scratch. The Imperial Manse hosts a magical universal constructor, an archive of everything that ever happened in the world, and some other magical resources that actually make that possible.
* In ''TabletopGame/{{Warhammer 40000}}'':
** The ''second'' most omnicidal faction in the setting is the Tyranids, a HordeOfAlienLocusts. If they have their way, the only life in the universe will be Tyranids floating in the depths of space; all life-supporting worlds will be reduced to airless, freezing rocks, the high end of a Class 6.
** The Necrons are among the purest, most literal {{Omnicidal Maniac}}s in any setting. Their purpose is, like the Tyranids, a Class 6 on the entire universe: quite literally the annihilation of all life, right down to bacteria, the harvesting of everyone's souls as delicious dessert for their [[PhysicalGod star-god masters]], and the complete destruction of the Warp, the plane of existence upon which souls exist.
*** Actually the Necron's ultimate goal is "merely" to sever the Galaxy from the Warp, destroying Chaos and also rendering all sentient life into soulless cattle for the C'tan. Thay most certainly don't want to wipe out all life. Hell, the whole reason they went to hibernation in the first place was that the Enslavers were wiping out nearly all life in the Galaxy, depriving the C'tan of the life energy of mortals. So they decided to go to sleep until life repopulates.
* Destroying all non-Terran life in the universe is the ultimate goal of the [[OmnicidalManiac insane]] Army of the Expeditionary Force in ''3:16 Carnage Amongst the Stars''.
[[/folder]]

[[folder:Video Games]]
* If left unbeaten for long enough a time, this would be the result of how Lavos from ''VideoGame/ChronoTrigger'' does his work, growing stronger and stronger, by "stealing/copying" the "best" DNA from life forms on a planet, desolating them by method of Class 4, then sending his own "spawn" off to new planets to do exactly the same thing on another planet.
* ''VideoGame/SuperMarioGalaxy'': [[BigBad Big, Bad Bowser]] himself holds the honors of not only ''inducing'' a Class X-4, but it actually ''goes through unprevented''. The only reason anything was "saved" was due to ''every last Luma in existence'' sacrificing themselves in unison to induce a new Big Bang and replace all that was lost--save for Mario and Rosalina, who carried them safely through the transition.
** The ultimate goal of ''VideoGame/SuperPaperMario's'' resident OmnicidalManiac, Count Bleck [[spoiler:and Dimentio]] is to cause a Class Z, but Bleck succeeds in destroying one universe, leaving a white void.
** Later, in ''VideoGame/LuigisMansionDarkMoon'', [[spoiler:King Boo]] comes really, really close to pulling either an X-4 or a Z.
* ''VideoGame/StarOceanTheSecondStory'' presents us with the Ten Wisemen. While nine of them seem to be just a bunch of jerkass, their leader, Indalecio, wants to destroy the entire universe by the Crest of Annihilation, which produces infinite amounts of mass and causes the universe to collapse. The party only makes it worse by killing him, which triggers the said DoomsdayDevice. This trend continues in the [[StarOcean3 third game]] of the series, where every enemy you hear of in the SpaceOpera portions of the game seem to be trying to one-up each other in terms of omnicidal mania.
* At the end of ''VideoGame/CommanderKeen 6'', it's revealed that the bad guy was planning to blow up the entire universe.
* ''VideoGame/{{Marathon}} Infinity'': The release of the Wrkncacnter wipes out everything in the universe, forcing our SpaceMarine hero to warp to an AlternateHistory and SetRightWhatOnceWentWrong.
* In ''[[VideoGame/PokemonDiamondAndPearl Pokémon Platinum]]'', Cyrus is planning to destroy and recreate the ''entire universe'' by summoning and {{c|apturedSuperEntity}}ontrolling [[OlympusMons Dialga and Palkia]] (the gods of, respectively, time and space).
* In ''VideoGame/{{Meteos}}'', the planet Meteo is hellbent on destroying every celestial body in the universe with signs of intelligence by pummeling them with phantasmagoric meteors until they ''explode''. Stars, planets, moons, asteroids, comets, dimensional anomalies...nothing is spared, and it's your job to stop it from doing that.
** This also includes the realms of Heaven and Hell, or at least their cosmic equivalents.
* Near the end of ''VideoGame/SystemShock 2'', the rogue AI [=SHODAN=] finds a way to alter reality using an experimental FTL engine. If she was not thwarted by the player, eventually the entire universe could be re-shaped to her liking.
* In the InteractiveFiction game ''Curses'', there is a control panel for the entire universe. Changing its settings is vital to proceeding in the game, but one of the controls is for modifying Planck's Constant, and tampering with it has predictably universe-ending results.
* If you're defeated by the final boss in ''RomancingSaGa3'', he causes an EarthShatteringKaboom that takes out the entire universe.
* If you lose in ''VideoGame/StarControl 2: The Ur-Quan Masters'', the Kohr-Ah faction of the Ur-Quan will eventually prevail in their Doctrinal War with the Kzer-Za faction, and they will proceed to take the Sa-Matra on a Death March to wipe out all non-Ur-Quan sapient life in the galaxy, and, after that, the rest of the universe. It is implied that the Kohr-Ah had, by that point, already wiped out all sapient life in one half of the galaxy, constituting approximately fifty-thousand sapient species.
* In ''VideoGame/JetsNGuns'', the main plot revolves around a universe-destroying quantum cannon stolen by Xoxx. [[spoiler:After you defeat him in the final stage. it is revealed that he already set the gun to go off, before he escapes through time to enslave a different universe. Once the gun fires, the only things surviving are your ship, asteroids, and a ShoutOut to Film/TheNeverendingStory. In the Gold Edition you find a restaurant, in which you upgrade your ship to be able to chase Xoxx down.]]
* [[BigBad Ultimecia]] from VideoGame/FinalFantasyVIII's true goal is to compress time and space down to one singular point.
** One could argue that it almost came close to a Class Z, as well. It seemed like her original goal was to make the universe such that only she could exist in it and, thus, basically become God. Yet towards the end of the final battle with her, it becomes apparent that what is ''really'' happening is different -- a good example is when she declared that all existence be denied, and if a party member falls, you get a message saying that they've been absorbed into time (something she ''doesn't'' control anymore at this point because Time Compression was halted halfway through). Sounds like she was getting in over her head; who really knows what would have happened if Ellone hadn't of halted Time Compression halfway through or the BigDamnHeroes had failed? It's quite possible Ultimecia could have destroyed herself in the process and reality would have been irrecoverably destroyed.
* If the [[EldritchAbomination Soulless Ones]] from ''{{Lusternia}}'' are fully released from their [[SealedEvilInACan prisons]], they'll devour every''one'' and every''thing'' in the universe ([[OmnicidalManiac including each other!]]), until only one bloated, amorphous mass remains.
* Happens in the [[MultipleEndings Bad End]] for ''VideoGame/Disgaea3AbsenceOfJustice''. To be specific: [[spoiler:Looking for a new adversary to slay and regain his former glory, Super Hero Aurum spends 200 years grooming Mao into what he hopes to be the strongest Overlord ever. In this ending, he ends up a little ''too'' successful]].
* In ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'', the main idea is that [[BigBad Alduin]] does this so a new universe can be created in cycles of time called "kalpas."
** The ultimate goal of the Thalmor is to attain divinity, believing that they were once divine souls who were trapped on Nirn when Lorkhan created the planet. Their current plan is [[spoiler: to completely stamp out worship of Talos, who is holding the physical world together with his presence. This will help unmake the world, which will allow the elves to return to their once-divine status.]]
* In ''VideoGame/{{Xenoblade}}'', it is revealed at the end of the game that [[spoiler:[[BigBad Zanza]] accomplished this in order to become a giant PhysicalGod. Afterwards, he kept causing Class 4 whenever his civilization became advanced enough to leave his body]].
* ''VideoGame/AsurasWrath'' reveals that [[spoiler: Chakravartin has been doing this to the universe since the beginning of existence itself, manipulating the universe to his liking and destroying and recreating it when it fails to meet his standards. Asura's refusal to become his heir convinces him that it's time to start again.]]
** Possibly a Class X5, as it's implied that he's been doing this to other universes as well.
* One character in ''IMissTheSunrise'' thinks the pessimist ending will lead to this. Another thinks it will lead to a utopia, with the player character as an omnipotent, benevolent God. [[spoiler:Even if you get that ending, you never find out which one was right.]]
* The second TastyPlanet game has the Goo devour progressively bigger things, eventually getting to planets, stars, entire galaxies, and eventually the fabric of space-time itself.
[[/folder]]

[[folder:Webcomics]]
* Due to a not-quite StableTimeLoop, the universe of Tryslmaistan in ''UnicornJelly'' has a storm that gradually grinds down everything in the universe into dust.
* In the ''Webcomic/SluggyFreelance'' story arc "GOFOTRON: Champion of the Universe," the main characters wind up in another world called the Punyverse, based off of sci-fi and anime parodies. A series of complicated events results in every piece of matter in the alternate universe being converted into energy. Only the main characters and a small spaceship manage to escape back the main universe. Later on, it's implied that the Tangle in the Web of Fate threatens to destroy, at the bare minimum, the entire main ''Sluggy'' universe, and possibly take down all the parallel ones along with it.
* ''Webcomic/TheOrderOfTheStick'': The Snarl destroys a whole pantheon of gods, then moves on to wipe out ''all'' of creation in under 30 minutes. The remaining gods managed to [[SealedEvilInACan lock it up]] in the process of remaking the world.
* ''IrregularWebcomic'', New Year's Eve, 2008. May have been a Class X-5, depending on one's definition of "universe".
* ''Webcomic/ABeginnersGuideToTheEndOfTheUniverse'' [[spoiler:actually takes place ''after'' the heat death of the entire universe.]] The only thing that [[spoiler:thwarts the Big Crunch and the birth of a new universe is that the Everyman, an anthropomorphic representation of the humanity's collective unconscious, somehow intervened at the last moments and created some buildings, air and light that are the only thing left within the void, forming the basis of the OntologicalMystery the comic begins with.]]
* In ''Webcomic/EightBitTheater'', Black Mage, as a manifest Nexus, has the ''potential'' to destroy the universe. The only thing that stops him doing so is that A) the assorted forces of the universe are smart enough to ''not'' let him die (as his physical being acts as a RestrainingBolt and it's only when he dies that he gains full access to his power), and B) [[spoiler: Chaos knocks him and the other Light Warriors back to their starting levels, which means he has to start all over again the whole process of getting access to enough of his power to destroy the universe]]. As long as he's still the Universe's CosmicPlaything, and it doesn't let him get access to enough of his power, he'll probably left at just ''attempting'' to act out his [[OmnicidalManiac Omnicidal tendencies]]
* ''Webcomic/{{Homestuck}}'': In the finale of Act 5, [[spoiler: Jack Noir destroys Universe B using the Red Miles, and Spades Slick destroys Universe A by killing [[ApocalypseMaiden Snowman]]. Both universes are then fused together inside The Tumor to create the Green Sun]].
** [[spoiler: The Scratch]] doesn't exactly destroy the universe, [[spoiler: [[RetGone it erases it from existence]] and [[ResetTime resets time]] to alter the starting parameters of the Session. However, everything and everyone in it or it's session will still [[DeaderThanDead not exist]] unless they can escape]].
** [[BiggerBad Lord English]] destroys every universe he enters, and devours their corpses. The aforementioned double apocalypse was just part of the procedure to summon him.
* In {{Narbonic}}, Mell and Artie find a videotape sent from the future. The world is a ruin, and Mell has taken over as President of the United States to keep the world from ending up like it is: the time machine needs all the energy in the universe to work, so she is destroying her entire universe to try to save Artie in a different timeline.
* In ''BobAndGeorge'', [[http://www.bobandgeorge.com/archives/000913c Dr. Wily destroys the strip's universe by killing the author]]. (it really was intended to end the world.)
* SonicTheComicOnline Shadow The Hedgehog uses the Chaos Emeralds to destroy the Special Zone killing everyone in the zone expect Sonic, Shadow and the Chaotix Crew and [[TheMafia The Family]].
[[/folder]]

[[folder:Web Originals]]
* According to various ''Franchise/TransformersTimelines'' stories, the universe of WesternAnimation/ChallengeOfTheGobots is at risk of this.
* In QNTM's [[Website/ThingsOfInterest Ed stories]], the original energy virus (the expanding-sphere version) would do this (it alters the fabric of the universe at a fundamental level and expands at the speed of light). It was created by the Eridanians, who hear in radio, in an attempt to block out Earth's radio noise from driving them all insane. (It was intended to form a hollow globe with E Eridani in the middle, that would forever cut it off from the rest of the universe. They got the formula a little wrong, and got the expanding-sphere version instead.)
* Happens in WebVideo/WhatTheFuckIsWrongWithYou after Space Guy tries to turn the filter back on.
* The Season 6 Finale of Sonic For Hire [[spoiler:almost ended up like this]] or worse.
* An old [[WebVideo/HitlerRants Downfall parody]] implied that [[spoiler:killing Fegelein will result with an imbalance in the universe, taking it (and possibly all other universes) with him.]]
[[/folder]]

[[folder:Western Animation]]
* Stimpson J. Cat, in the ''WesternAnimation/RenAndStimpy'' episode "Space Madness", cannot resist pushing the "jolly, candy-like" [[BigRedButton History Eraser Button]].
* In the ''WesternAnimation/{{Futurama}}'' episode "Anthology of Interest I", the What-If Machine predicts the entire universe being destroyed as a consequence of Fry not being frozen. Given that his removal would create at least one paradox and without him, the Brainspawn would have destroyed the universe, it's amazingly accurate.
** In "The Beast with a Billion Backs", the [[FunWithAcronyms Democratic Order of Planets]] utilizes a [[FunWithAcronyms Universe-to-Universe Missile]] in an attempt to destroy Yivo's universe and free our universe from [[NaughtyTentacles tentacle terror.]]
** Fry, Bender, and Farnsworth watch this happen in "The Late Philip J. Fry" as they warp forward in time to the end, watching the universe explode, only to watch a new one exactly identical to it emerge immediately afterward in a new Big Bang.
*** It wasn't identical...it was a few feet lower then the old universe, resulting in the time machine crushing and killing the trio from the new universe. Hence neatly avoiding any issues with duplicates.
* Played for laughs in ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy'' when Mandy smiles, causing the the destruction of reality in a SugarWiki/{{Funny Moment|s}} that ends with them having replaced WesternAnimation/ThePowerpuffGirls.
* During the Pizza Planet segment of ''WesternAnimation/ToyStory'', Andy, explaining the backstory to some piece of media to his mother, blurts out "...and the ''universe'' explodes!" Considering the scene in question focuses more on Woody trying to get Buzz to jump into Molly's stroller, [[NoodleIncident we never quite figure out what that was all about]]; whatever it was, though, it was an example.
* In ''WesternAnimation/BatmanTheBraveAndTheBold'''s AnimatedAdaptation of ''ComicBook/EmperorJoker'', during the VillainSong, "WheresTheFunInThat", the Joker causes an X-4, destroying the whole universe, leaving an empty white void with himself, his henchmen, Batman, and Bat-Mite. He then builds a room made of cards in its place. Don't worry, though, Bat-Mite eventually gets repowered to SetRightWhatOnceWentWrong.
[[/folder]]

[[folder:Real Life]]
* The most likely ultimate scenario is currently considered to be the Heat Death of the universe. Thermodynamics dictates that, due to entropy, eventually (in about 100 trillion years) all energy in the universe will be used up. There will no longer be any transmission or conversion of energy or reactions of any kind. The stars will burn out, everything will freeze and go dark, and eventually all matter and energy will be sucked up by Black Holes, which, [[TimeAbyss even later]], will unravel themselves from Hawking Radiation, leaving only an absolutely cold, dark, silent, empty vacuum expanding into infinity for eternity.
* Three words: [[http://en.wikipedia.org/wiki/False_vacuum#Vacuum_metastability_event Quantum Vacuum Collapse.]]
** The quote itself would be Crowning material if there were such a thing as a Crowning Moment of Doom.
-->'''Coleman and de Luccia''': [...] One could always draw stoic comfort from the possibility that perhaps in the course of time the new vacuum would sustain, if not life as we know it, at least some structures capable of knowing joy. [[DownerEnding This possibility has now been eliminated.]]
** Similar theories seem to indicate that there is an upper limit to the "knowledge" we can have of any given area of spacetime. (Heisenberg and quantums and a bunch of other stuff I only personally understand at a high level, and a complete description would probably be a stack of research papers a mile thick.) If we were ever able to observe absolutely everything in a given region of space, it would result in an inability of spacetime itself to continue function, causing ... something to happen. This concept is toyed with in ''Literature/BloodMusic'' by Creator/GregBear.
* The [[http://en.wikipedia.org/wiki/Simulation_hypothesis Simulation Hypothesis]] puts forward the possibility that reality as we know it is no more than a simulation. If its creators or some other outside force were to turn it off...
** If they're running more than one simulation, this would be X-5.
** [[Anime/DigimonAdventure Wait, you mean to tell me that we're in one giant computer game]] [[StarOceanTillTheEndOfTime and none of this is actually real?]]
* It all depends on what the true nature of Dark Energy is. One hypothesis is the Big Crunch, stating that the universe will slow down in its expansion and eventually go into a sort of reverse Big Bang, collapsing back into a singularity. The more optimistic Big Bounce idea is that the Big Crunch happens, but the reversion of the universe into a singularity again will trigger another Big Bang. The universe thus remakes itself with a bang and a crunch through cycles of rebirth, maybe for all eternity.
** Contrariwise, the Big Rip hypothesis suggests that Dark Energy will eventually accelerate the Universe so fast that it will even overpower the energy bonds that hold matter together, so that even subatomic particles will be ripped apart. Strangely, this acceleration would still continue until it reaches the speed witnessed during the inflationary period of the Big Bang, allowing the creation of new particle-antiparticle pairs from the vacuum energy, just as it did originally. In this scenario, again, the destruction of our Universe potentially brings about the birth of a new much larger and potentially much richer Universe.
[[/folder]]
----