[[quoteright:300:[[Manga/JoJosBizarreAdventure http://static.tvtropes.org/pmwiki/pub/images/enyajustice_1023.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 the 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 evil 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 is trying to bite you. Sometimes the fog itself is the threat. No mere mist, the Fog of Doom is often poisonous, or acidic, or causes men to go mad. Other times, the Fog of Doom conceals other threats that come out of the mist to take and devour you so quickly that your friends don't even know you're gone until they look around and see you're just not there.

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

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

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

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!Examples:

[[foldercontrol]]

[[folder:Anime And Manga]]
* ''Manga/JoJosBizarreAdventure'' had mist that turns you into a zombie.
* 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.
[[/folder]]

[[folder:Fan Works]]
* An industrial acccident 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]]

[[folder:Film]]
* 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.
[[/folder]]

[[folder:Literature]]
* A strange ecosystem came out of the fog in Creator/StephenKing's ''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...
* MichaelMoorcock's ''ElricOfMelnibone'' 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''.
* In William King's TabletopGame/{{Warhammer 40000}} 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 ''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 ''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.
* ''TalesOfTheMagicLand'' (a series of loose Russian translations of the ''WizardOfOz'' books) 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 ''{{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. They're not quite as GenreSavvy as their ponies, and end up captured by a [[OurGhostsAreDifferent Barrow-Wight]].
[[/folder]]

[[folder:Live Action TV]]
* ''Series/StarTrekTheOriginalSeries'' episode "Obsession", with the star traveling vampire cloud.
* Mistfall in the ''Series/DoctorWho'' serial "[[Recap/DoctorWhoS18E3FullCircle Full Circle]]".
* 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.
[[/folder]]


[[folder:Tabletop Games]]
* The mist-loving Sea Zombies in the DungeonsAndDragons ''Greyhawk Adventures'' supplement were [[strike:a ripoff of]] inspired by John Carpenter's zombies.
** DungeonsAndDragons also features air elementals, crimson deaths, vampiric mists, and mist dragons.
** [[DungeonsAndDragons Ravenloft's]] most iconic set-piece is 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 was 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 VillainsAndVigilantes adventure ''Devil's Domain'', killing demons released a cloud that caused humans to go insane and attack you.
* London in ''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.
[[/folder]]

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

[[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 ''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 ''FinalFantasyCrystalChronicles''.
* There was a fog in ''BlueDragon'' that inebriates its inhalers. And it's at sea. Close to rocks to run into.
* 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, ''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.
* ''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 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]].
* ''{{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.
[[/folder]]

[[folder:Western Animation]]
* 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 SelfDemonstrating/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'' has XANA entering the real world as a gas/liquid when its 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.
[[/folder]]

[[folder:Real Life]]
* London is known for its OminousFog, thanks to much of the city being in a large river valley kn own 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 Friday the 5th of December to Tuesday the 9th of December, London was enshrouded with what has come to be called the Great Smog of 1952. One of the worst pollution episodes in history, the Great Smog killed nearly 4000 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, nearly half of 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 2000 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. Carbon monoxide is quite a dangerous gas.
* Many chemical weapons take on this feature when released, from the viewpoint of the victims. This sometimes crosses over with DeadlyGas.
[[/folder]]

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