[[quoteright:300:[[Manga/JojosBizarreAdventureStardustCrusaders http://static.tvtropes.org/pmwiki/pub/images/fogofdoomjustice.jpg]]]]
[[caption-width-right:300:[[SkullForAHead In case you weren't sure if this fog]] [[ObviouslyEvil was evil or not.]]]]

->''"I don't know what happened to Antonio Bay tonight. Something came out of the fog and tried to destroy us. In one moment, it vanished. But if this has been anything but a nightmare, and if we don't wake up to find ourselves safe in our beds, it could come again. To the ships at sea who can hear my voice, look across the water, into the darkness. Look for the fog."''
-->-- '''Stevie Wayne:''', ''Film/TheFog (1980)''

This isn't normal mist that comes at a bad time, obscuring vision or providing dramatic tension. It's certainly not that serene mist that comes just after a gentle rain... no, this fog is malevolent and out to get you.

Everyone knows that an OminousFog is a bad sign in movies, books, and television shows. One of the most sure-fire ways of generating that edgy feeling of paranoia is to enshroud the setting in a dense, opaque mist. Because anything could be hiding in there...

An OminousFog turns into a Fog of Doom when it's hostile. Sometimes the fog itself is the threat. No mere mist, the Fog of Doom is often poisonous, acidic, or causes men to go mad. Other times, the Fog of Doom conceals other threats that come out of the mist to take you so quickly that your friends don't even know you're gone until they look around and see you're not there.

Either way, you'd better avoid walking into a mist at all costs.

This trope can also include other sight obscuring conditions such as dust storms, supernatural darkness, or smoke; fog is simply the most common mechanism to achieve the effect.

For things that can turn themselves into smoke, see SuperSmoke. For ordinary poisons, see DeadlyGas.



[[folder:Anime & Manga]]
* ''LightNovel/FateApocrypha'': Jack the Ripper can shroud the area in a poisonous fog. The fog also fulfills one of the [[SituationalSword conditions]] needed for Jack to use [[OneHitKill Maria the Ripper]].
* ''Manga/JoJosBizarreAdventure'' had mist that turns you into a zombie.
** For better clarification the [[FogOfDoom mist]] is a [[FightingSpirit stand]] called [[TarotMotifs Justice]] controlled by the old lady at the bottom, [[ShoutOut Enya Gail]]. Justice can control the body, living or dead, through wounds created by Enya.
* The ninjas of Kirigakure (meaning "Hidden Mist") in ''Manga/{{Naruto}}'' use fog for their silent killing techniques. So, it's not the fog trying to kill you, but ninjas ''in control of the fog'' trying to kill you.
** The Godaime Mizukage takes this a step further. Like the village she leads, she can use mist-like techniques. The difference is, hers can fill a room and literally ''melt'' people.
* Somewhat, in one of the ''Manga/{{Pokemon}}'' manga there was a Haunter called the "Black Fog". Yeah, he wasn't friendly.
* In ''Franchise/SailorMoon,'' Sailor Mercury can produce this with her Mercury Aqua Mist attack ([[BubbleGun Sabão Spray]] in TheNineties [[Anime/SailorMoon anime]]), producing a concealing fog that gives comrades an opening to attack an enemy unawares. (The fog itself had no special properties; she was TheSmartGuy rather than having much in the way of offensive power. She gets more direct means of attack as once or twice per season the gang gets more powers.)

[[folder:Fan Works]]
* An industrial accident in Cloudsdale produces the titular fog in Fanfic/FlashFog. It's a miles-wide sphere of cloud that simply can't be manipulated and will eventually set "solid". Plus, the interior of it is cold enough that prolonged exposure can freeze Earth Ponies to death. Since it's spread itself over a large area of farming country, it's become very disruptive and has to be gotten rid of as quickly as possible.

[[folder:Films -- Live-Action]]
* In Creator/JohnCarpenter's ''Film/TheFog'', undead pirates came out of the mist to seek their revenge.
* In Creator/TimBurton's ''Film/SleepyHollow'' the fog actually reaches out and puts out the torches around the village before the headless rider comes out of it.
* ''Film/TheTenCommandments'' (1956). The tenth plague that kills all the firstborn in Egypt is depicted as this.
* ''Film/TwentyEightWeeksLater'' had the poison gas the US Army unleashed on London in its attempt to kill off the remaining Infected.
* Whereas in ''Film/PlanetTerror'' and ''Film/TheReturnOfTheLivingDead'', it's the fog that creates the zombies in the first place.
* The whole concept of ''Literature/TheMist''.
* ''The Trollenberg Terror'' (aka ''Film/TheCrawlingEye'') has a giant, disembodied eye emerging from its hiding place inside a radioactive cloud to attack its victims.
* ''Film/WhoKilledTheElectricCar'': The infamous LA smog, which California lawmaker Alan Lowenthal described as the "black cloud of death". The desire to get rid of fog was what pushed the California Air Resources Board ([[FunWithAcronyms CARB]]) to require car companies to build the electric car.

* A strange ecosystem came out of the fog in Creator/StephenKing's ''Literature/TheMist''.
* Creepy fog-cloaked areas called "thinnies" are a rare, but deadly and unpredictable hazard in King's ''Franchise/TheDarkTower'' series.
* In Creator/LarryNiven's ''For A Foggy Night'', the mist isn't actually mist, but is rather times when the various alternate timelines intermesh. When you walk out into a fog, you're actually walking into an alternate world... its just that most of the time the "alternate" is so close to your original world you never notice. But sometimes, just sometimes, you cross over into a world that's completely different...
* Creator/MichaelMoorcock's ''[[Literature/TheElricSaga Elric of Melnibone]]'' has the Groaning Mist, which after enveloping its victims attempts to drive them insane with hallucinatory voices whispering of their fears and inadequacies.
* In Creator/FritzLeiber's [[Literature/FafhrdAndTheGrayMouser Lankhmar]] story ''The Cloud of Hate'', the titular cloud turns people into killers.
* ''Literature/TheWheelOfTime'' has a city full of murderous mist. Touching the corrupted fog of [[NamesToRunAwayFromReallyFast Shadar Logoth]] will either kill you outright ''or'' infect you with an eventually-lethal HatePlague. Originally, the fog was contained in the city, but once one of the infected escaped into the countryside, it came with him, and is now (under the command of the aforesaid infectee) capable of forming spontaneously in unexpected places and ripping apart everyone within.
* The Mind Fog is a creepy and illegal magical effect in ''Literature/TheDresdenFiles''. It renders those touched by it dumbstruck and defenseless to anything unaffected by it.
* In William King's TabletopGame/{{Warhammer 40000}} Literature/SpaceWolf novel ''Grey Hunters'', the Chaos forces cause a green and yellow fog to boil up. It obscures vision, allows their enemies to sneak up, and contains some kind of poison.
* ''Literature/TheFog'' from James Herbert back in 1975, not related to the John Carpenter film of the same name. In this novel, a fog descends over Britain that turns almost the entire population ''insane''.
* M.P. Shiel's 1901 novel ''The Purple Cloud'' has nearly the entire human and animal population of Earth being [[DepopulationBomb killed off]] by the mysterious title cloud.
* The ''Literature/TalesFromCampCrystalLake'' series of books by Eric Morse [[note]] ''Mother's Day'', ''Jason's Curse'', ''The Carnival'' and ''Road Trip''[[/note]] all feature a yellow fog which seems to make everyone feel more negatively, lubricating the lethal intentions of whomever finds the [[BecomingTheMask hockey mask]] as well as the FinalGirl.
* In Creator/RobertEHoward's ''Franchise/ConanTheBarbarian'' story "Literature/BlackColossus", the EvilSorcerer foe sends a mist over the desert to block his army's sight.
* Features in ''Literature/TheHungerGames''. The fog in question is a kind of nerve gas that burns the skin and causes seizures and muscle failure.
* In ''Literature/SeptimusHeap'', the bank of Fog surrounding the House of Foryx conceals an Abyss.
* ''Literature/TalesOfTheMagicLand'' has a book aptly named ''The Yellow Fog'' where a witch named Arachna who attempts to subdue the Magic Land with the titular fog. While not lethal (it's meant to subdue rather than exterminate, after all), it has several negative effects: it's toxic, for one, and it also blocks off the sun leading to intense cold in the usually winterless Magic Land.
* In ''Literature/{{Mistborn}}'', the mysterious threat called the Deepness is actually the normally benign mists, which [[GodOfEvil Ruin]] intensified until they form a crop-killing particulate winter.
* An early example can be found in ''Literature/TheWarOfTheWorlds''. The Martians use a weapon called Black Smoke that acts very much like a semi-sentient, malevolent killing black mist. It's described in the book as moving almost like a living thing to cut off escape and trap its victims.
* The Smog in UnLunDun is effectively a sentient version of the smog that covered most of industrial-revolution London, and as such, is ''very'' lethal. It is also able to possess people to an extent, creating hideous creatures known as 'Smombies' and [[spoiler:has been possessing Unstible for some time]].
* In ''Literature/TheLordOfTheRings'', the hobbits run into one of these on the Barrow Downs, and end up captured by a [[OurGhostsAreDifferent Barrow-Wight]].
* In the first of the ''Literature/{{Deathlands}}'' novels, the Darks are protected by this trope, apparently a pre-WW3 weapon called Project Cerberus used to guard the MAT-TRANS PortalNetwork found in the Darks.
* In ''Literature/TheTraitorSonCycle'', before he manages to get a more corporeal form, [[spoiler:Ash]] manifests as a cloud of thick black fog stalking the underground of the Harndon palace.
* In the ''Weird Tales'' short story "Literature/TheNightWire", two newsdesk-workers receive incoming reports of a city they've never heard of being overwhelmed by a mysterious fog that consumes people. It's unclear if the town actually existed, [[spoiler: but ''some'' creepy force clearly does, because one of the newsmen dies while listening to the wire yet ''keeps on transcribing'' the report.]]

[[folder:Live-Action TV]]
* ''Series/StarTrekTheOriginalSeries'' episode "Obsession", with the star traveling vampire cloud.
* Mistfall in the classic ''Series/DoctorWho'' serial "[[Recap/DoctorWhoS18E3FullCircle Full Circle]]". [[spoiler: K9 analyzes the fog and declares it non-toxic.]]
** In the ''AudioPlay/BigFinishDoctorWho'' audios, the Eminence is an EldritchAbomination presented as a sentient fog capable of reanimating the dead and making them its immortal warriors, so horrifyingly feared armies are mobilized at the mere sighting of a single Eminence soldier.
* ''Series/{{Sherlock}}'' gives us the fog in ''The Hounds of Baskerville''. [[spoiler: It contains a drug which makes the mind extremely susceptible to fear and stimulus.]]
* A World War I era episode of ''Series/YoungIndianaJones'' depicts a poison gas attack in this manner. For added terror, German [[KillItWithFire flamethrower teams]] emerge from the gas cloud soon afterwards.
* In the ''Series/{{Supernatural}}'' episode [[Recap/SupernaturalS02E22AllHellBreaksLoosePartTwo "All Hell Breaks Loose, Part Two" (S02, Ep22)]], black smoke explodes from the Devil's Gate as the forces of hell are released.
* Episode 4 of ''Series/TheCrown2016'' covers the Great Smog of 1952. As detailed in RealLife below, it was a noxious soup of fog and vehicle exhaust that was exacerbated by coal smoke from furnaces. The hospitals are quickly overwhelmed by respiratory patients and both Winston Churchill's opponents and fellow Conservatives try unavailingly to convince him that the smog is a serious problem of human origin--it gets so bad that they encourage the young Queen Elizabeth to intervene with him. He only realizes the depth of his mistake when the lack of visibility results in his young secretary being fatally struck by a bus, and he sees just how swamped the hospital is when he visits the morgue. The ending titles of the episode inform viewers that 4,000 deaths in the following months were attributed to the smog, but more recent research raises the estimate to ''12,000.''

* Lights Out by Arch Oboler had a classic story called "The Dark," about a fog that turns people inside out, famously referenced in ''WesternAnimation/TheSimpsons'' Treehouse of Horror V. Originally broadcast in the early 40s, the original version was lost, but a 1962s abbreviated version Oboler made in 1962 still exists and is creepy as ever.

[[folder:Tabletop Games]]
* ''TabletopGame/DungeonsAndDragons'':
** The mist-loving Sea Zombies in the ''Greyhawk Adventures'' supplement were inspired by John Carpenter's zombies.
** ''D&D'' also features air elementals, crimson deaths, vampiric mists, and mist dragons.
** The most iconic set-piece of ''TabletopGame/{{Ravenloft}}'' are The Mists that hang over most of the Land, and this is often used as a [[DownTheRabbitHole means to pluck players out of their home world]]. It gets to a point where experienced players will run screaming from the slightest sign of mist. One of the nastiest salient powers mentioned in the ''Ravenloft'' supplement ''Van Richten's Guide to Vampires'' was the possibility of a Patriarch vampire using its energy-drain ability ''while in mist-form''. This was a particularly terrifying prospect under 2nd Edition rules, when there was virtually no way to fight back against a gaseous-form opponent.
** There is also a spell call Murderous Mist, which was a druid spell that created hot steam that could boil your eyes. Then again, there are the more classic Stinking Cloud, Cloudkill, and Acid Fog spells.
* In the ''TabletopGame/VillainsAndVigilantes'' adventure ''Devil's Domain'', killing demons released a cloud that caused humans to go insane and attack you.
* London in ''TabletopGame/UnhallowedMetropolis'' is cloaked in heavily toxic smog. Going outside without a gas mask or at least a damp cloth to cover your mouth and nose causes unconsciousness in short order, and death not too long after. Direct sunlight penetrating the smog layer is rare, and on the worst days, it blots out the sun entirely. There's nothing supernatural or actively malevolent about it, but that's a small comfort.
* In ''TabletopGame/HoylesRulesOfDragonPoker'', when there's fog outside, all cards are hole cards and the first two rounds of betting are done blind.

* In ''Toys/{{Bionicle}}'', Lesovikk encounters a sentient acid cloud while he's trapped in a LotusEaterMachine. He easily defeats it by [[BlowYouAway blowing it away]].

[[folder:Video Games]]
* ''VideoGame/LegendOfLegaia'' provides a misguided BigBad who creates the Fog of Doom, which warps the titular {{Utopia}} into a CrapsackWorld. But otherwise, [[{{Irony}} the fog was harmless]]. Unless you were wearing a Seru, as the fog turned those, and anyone who was wearing one, into a horrible monster. And given that, before the fog, everyone was using them non-stop to do everything, it was a fog of doom. Oh, and if you ran into one of those previously mentioned monsters that were lurking in the mist just outside of the few remaining safe havens, you were screwed, since ordinary weapons were worse than useless against them.
* In ''VideoGame/CityOfHeroes'', Dark Astoria is a zone covered in a frustratingly opaque mist, filled with arcane and supernatural enemies. For extra points, all of the neighborhoods and landmarks in Dark Astoria are named after old school horror authors, filmmakers, and characters. Adding to the creepy lethality of the zone, players can see vague images of the zone's long-dead inhabitants in the mist... who fade upon approaching.
* ''VideoGame/FinalFantasyIX'''s Mist was the source of many a scary monster. On the other hand, it was also the source of many a [[spoiler: black mage.]] The Mist was created by [[spoiler: the Iifa Tree, which processed the souls of the dead into Mist. This then was to clear Gaia of life to make room for the denizens of Terra. It had the bonus effect of making people bloodthirsty, accelerating the whole process.]]
* The miasma of ''VideoGame/FinalFantasyCrystalChronicles''.
* There was a fog in ''VideoGame/BlueDragon'' that inebriates its inhalers. And it's at sea. Close to rocks to run into.
* There is a red fog that chases Heather in ''VideoGame/SilentHill3'' that will kill her if she lets it catch up with her. Some of the early pre-release materials for ''VideoGame/SilentHillOrigins'' suggested that the town's OminousFog would cross the line to become an active, amorphous enemy. The game switched production teams midway through development, and though a later sequel, ''VideoGame/SilentHillHomecoming'', did feature an otherwise corporeal monster named "Smog", the Fog of Doom idea never panned out.
* The fog that appears in the TV World in ''VideoGame/{{Persona 4}}''. It causes fatigue for those not wearing special glasses that allow them to see in it. It crosses over to the real world every so often and when it recedes, corpses are found in high places. [[spoiler:Near the finale of the game, the fog starts seeping into the real world, and it's revealed that those exposed to the fog for too long will eventually turn into Shadows -- which is how Izanami, the BigBad behind it all who you fight in the True Ending, wants things]].
* The Kvaldir, also known as the walkers of the fog, from ''VideoGame/WorldOfWarcraft'' are ghostly sea raiders who only show up in areas of very heavy fog. There's also the noxious orange mist that passes for atmosphere in the zombie-infested Plaguelands. In high enough concentrations, it's a vector for [[ThePlague the Scourge]].
* In ''VideoGame/LostKingdoms'', the black mist contains monsters and is the influence of the BigBad. A SideQuest reveals a scientist who tried to save his hometown, but ended up creating a white mist containing ''weird'' monsters.
* In ''VideoGame/CastlevaniaSymphonyOfTheNight'', Alucard can actually change into a playable Fog of Doom once you've found the right items: with the "Form of Mist" and "Gas Cloud" relics, his mist form is invincible and causes damage to any enemies within it, while constantly draining a small amount of MP. It's every bit the GameBreaker it sounds like, though you can only get it near the end of the game.
* The creepy fog in Sei-an City in ''VideoGame/{{Okami}}'' is slowly killing everyone in the city. Turns out it's caused by a monster called Blight, [[spoiler:which is living in the Emperor's Stomach]].
* ''VideoGame/DeadlyPremonition'' has a purple fog which drives people insane.
* ''Franchise/TheLegendOfZelda'':
** The mist in the Earth Temple of ''VideoGame/TheLegendOfZeldaTheWindWaker'' is infamous for not only robbing you of your item use, but also for concealing none other than [[GoddamnBats the dreaded Floormasters]].
** ''VideoGame/TheLegendOfZeldaTwilightPrincess'', once you head to the Forest Temple in human form with Midna, you have to go through a mass of purple fog following a monkey with your lantern. The fog doesn't affect your enemies, sadly, making it very annoying when you're running along and the monkey suddenly stops in terror and you careen into purple death. The penultimate dungeon also has black, ashy mist that traps you in wolf form as long as you stand in it.
* ''VideoGame/{{Freelancer}}'' has a number of [[SpaceClouds nebulae]] that will [[HollywoodAcid corrode your hull]], bombard you with radiation, or conceal [[SpacePirates pirates]] or [[EldritchAbomination Nomads]].
* It's just like they say in VideoGame/FirstEncounterAssaultRecon : FUCKING RUN!!!
* In ''VideoGame/DwarfFortress'' the surfaces of evil regions have a variety of clouds of randomly named materials ("execrable soot", "accursed gloom", etc) which cause randomly determined symptoms, ranging from mild dizziness to all of your internal organs rotting to becoming a zombie.
* ''VideoGame/RescueOnFractalus'': The acidic atmosphere of the eponymous planet both reduces visibility and dissolves the flight suits of exposed pilots.
* ''VideoGame/{{Fallout 4}}'''s Far Harbor DLC has [[ExactlyWhatItSaysOnTheTin The Fog]], which may carry [[DeadlyGas radioactive poison]], conceal monsters such as [[DemonicSpiders Fog Crawlers]], or cause visitors such as the Sole Survivor to [[MushroomSamba hallucinate]].
* In ''Beyond Zork'' eldritch vapors are monsters that appear as clouds of fog and will steal the player's items (as well as tickling the player and touching the player in inappropriate places).
* While it's not really explained how it works, death fog in ''VideoGame/DivinityOriginalSinII'' instantly kills anyone who enters a cloud of it, making it a deadly obstacle and potent weapon. It's also apparently mass manufactured, and stored in crates and barrels, and someone has stolen a very large shipment of it...

[[folder:Web Comics]]
* ''Webcomic/SoulToCall'': Not only do abominations appear out of the Fog, but people who wander in tend not to wander out...

[[folder:Western Animation]]
* The ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' two-parter "The Crystal Empire" gives us a sentient, shadowy example in the form of King Sombra, who takes advantage of this alternate form to completely surround his former PlaceOfPower while waiting for any and all openings to retake it. While he's in this state, anyone or anything he comes into contact with is infected with black crystals that can cause various BlackMagic effects.
* The "[[Recap/TheSimpsonsS6E6TreehouseOfHorrorV Treehouse of Horror V]]" episode of ''WesternAnimation/TheSimpsons'' had a fog that turns people inside out (a spoof of [[http://en.wikipedia.org/wiki/Lights_Out_(radio_show)#The_Arch_Oboler_era Arch Oboler's 1937 radio play "The Dark"]] on the program ''Lights Out'', which featured a similar fog and [[http://en.wikipedia.org/wiki/Treehouse_of_Horror_V#Production allegedly]] had scared writer David X. Cohen as a child).
* One episode of ''WesternAnimation/DangerMouse'' has the "Dreaded Fog Monster of Old London Town". It being a kid's cartoon, the Fog is more of a prankster than a threat.
* ''WesternAnimation/XiaolinShowdown'' had the Woozy Shooter. It induces a MushroomSamba in its victim, and the user can take advantage of that.
* The cloud of Joker Venom that ComicBook/TheJoker doses Gotham with in one ''WesternAnimation/BatmanTheAnimatedSeries'' episode could qualify as the "insanity-inducing" variant... But you had to be exposed to it for a long time in order for the insanity to take effect.
* ''WesternAnimation/CodeLyoko'':
** XANA's polymorphic specters enter the real world as a gas/liquid when their schemes involve possessing something, which sometimes ends up being even more gas.
** This is also [[spoiler:XANA's final form upon being defeated. After being destroyed in Lyoko, William is depossessed and XANA formulates in a gaseous fog before dissolving.]]
* ''WesternAnimation/TheLegendOfKorra'' has a somewhat chilling example for a kids' show with the "Fog of Lost Souls'', which eternally imprisons its victims in their most traumatic memories.
* The very premise of ''WesternAnimation/SpiralZone'': half of the planet is covered by an artificial fog that turns people into mindless zombies and gives them severe physical deformities.
* ''WesternAnimation/CourageTheCowardlyDog'' has the Fog Spirit from the 2014 CGI special episode "The Fog of Courage". The spirit awakens when Courage digs up a necklace that belonged to the spirit's dead lover and engulfs the farm in its fog in an attempt to get it back. It isn't actively malicious at first despite clearly being dangerous, but it's when Eustace tries to bargain with it over the amulet, which he thinks is valuable, that the Fog Spirit becomes hostile.

[[folder:Real Life]]
* London is known for its OminousFog, thanks to much of the city being in a large river valley known as the Thames Basin. Combine that with extensive industrialisation and [[NoOSHACompliance a lack of environmental regulations]] and you have a recipe for this trope. Smog conditions got bad enough to be a public health hazard fairly regularly, but the last and worst incident was in 1952: From December 5th to December 9th, London was enshrouded in what has come to be called the Great Smog of 1952. One of the worst pollution episodes in history, the Great Smog killed nearly 4,000 people, and hospitalized nearly 100,000 more from respiratory tract infections and hypoxia (the inability to get enough oxygen). This finally convinced the government that enough was enough, and the UK's first Clean Air Act was passed soon after.
** A [[http://en.wikipedia.org/wiki/1948_Donora_smog nearly identical situation]] happened in the mill town of Donora, PA in 1948, which led to the death of 20 and the infection of nearly 7,000, almost half the town's population, from respiratory illness. The smog also left many survivors with lasting illness. The event is still considered one of the worst environmental disasters in US history.
* Take the inherent danger of driving in thick fog with some Californians' ''infamous'' driving habits...and you have a recipe for disaster.
* On August 21, 1986, volcanic activity released a massive amount of carbon dioxide into Lake Nyos in Cameroon. The gas emerged from the water's surface as a massive cloud that (due to CO[[subscript:2]] being heavier than air) hugged the ground like a fog bank. [[http://www.youtube.com/watch?v=JzchV_gQG10 This "death fog" engulfed three lakeside villages, killing approximately 2,000 people.]]
* Time and medical statistics have made it increasingly clear that the dust-clouds from the World Trade Center attacks constituted a slow-acting example of this, given the number of rescue personnel who have succumbed to respiratory disease and cancer after breathing in those dust particles.
* The 2010 forest and peat fires in Central Russia caused a Smoke of Doom in many Russian cities including Moscow.
* Many chemical weapons take on this feature when released, from the viewpoint of the victims. This sometimes crosses over with DeadlyGas.