[[quoteright:350:[[Film/GodzillaVsHedorah http://static.tvtropes.org/pmwiki/pub/images/hedorah2.jpg]]]]
[[caption-width-right:350:And remember, this thing is [[GreenAesop your fault]].]]

You can smell it from a mile away.

A big, horrific pile of glop. Perhaps it's made of toxic sludge from a CorruptCorporateExecutive's industrial plant, or perhaps it's merely a colossal pile of dung.

But it's alive.

The Muck Monster is a living embodiment of filth and slop, the GreenAesop tends to be his stomping grounds. Nothing tends to hammer an anti-pollution message home like an colossal, animate pile of crap. Plants die from this beastie's approach; sometimes animals and even people bite the dust from being in mere proximity to this abomination.

Compare BlobMonster, which is more transparent (and generally less smelly), TalkingPoo.
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!!Examples:
[[foldercontrol]]

[[folder:AnimeAndManga]]
* Ginta uses Babbo: Alice to dispel this curse off "Gramps" in episode 97 of MarchenAwakensRomance.
* ''SpiritedAway'' has the [[spoiler:River Spirit that was mistaken for a]] Stink God, who is literally just a moving pile of sludge with eyes. His smell is so bad that it makes everyone's eyes water and makes all of the food around him rot. [[spoiler:It's due to the pollution in he river he inhabits.]]
[[/folder]]

[[folder: ComicBooks]]
* {{Batman}}'s enemy Clayface [[LegacyCharacter (all eight of them)]] fit the Trope in some way, although some are more humanoid than others. The worst part is, all of them [[WasOnceAMan were once human]].
[[/folder]]

[[folder:{{Film}}]]
* ''Film/{{Creepshow 2}}'' had a large, flat monster resembling an oil slick, that dissolved any flesh it touched, inhabiting a lake.
** That was an adaptation of ''The Raft'', a short story by Creator/StephenKing.
* ''[[Film/GodzillaVsHedorah Godzilla vs. The Smog Monster]]'', villain Hedorah has to be the most famous example of this trope, and it shows why one must never let alien spores come into contact with industrial waste, lest it [[MetamorphosisMonster mutate]] into a giant tadpole sludge demon that can drop lethal acid as it flies.
** Hedorah comes with a MeaningfulName with a dash of ExactlyWhatItSaysOnTheTin as the name is derived from ''hedoro'' which is Japanese for "Sludge of Industrial Waste".
* ''The H-Man'' is an earlier iteration of this, but explicitly radioactive (hence the name). It {{was once a man}}, and now must eat other humans in order to retain its shape.
* ''{{Dogma}}'' had a demon, the Golgothum, constructed from crap - specifically, the crap of all the prisoners crucified at Golgotha ([[JesusChrist yes, including Him]]). He's defeated by deodorant (which "knocks out strong odors").
* Armageddon from ''TheReturnOfHanuman'' is a monster formed from a volcano, mostly because of the many inorganic trash contained inside and [[spoiler:activated when Rahu and Ketu's staff went inside of the volcano]].
* ''[=MonSturd=]''. It's like ''Film/JackFrost1997'', except the SerialKiller was genetically fused with shit instead of snow.
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[[folder:{{Literature}}]]
* [[BigBad Visser Three]] from ''Literature/{{Animorphs}}'' is a shapeshifter with two forms like this, seen in ''The Weakness'' and ''The Hidden'' respectively.
* During the lifeforce crisis in [[Literature/{{Discworld}} Reaper Man]], one of the [[WizardingSchool Unseen University's]] ''compost heaps'' comes to life. It attacked the gardener and dissolved its way through the main door before the wizards [[StuffBlowingUp blew it up]] with a bottle of [[BlazingInfernoHellfireSauce Wow-Wow sauce]].
* The deities [[http://en.wikipedia.org/wiki/Clark_Ashton_Smith_deities#Abhoth Abhoth]] and [[http://en.wikipedia.org/wiki/Clark_Ashton_Smith_deities#Ubbo-Sathla Ubbo-Sathla]] in Creator/ClarkAshtonSmith's CthulhuMythos stories.
* The title creature in ''Slime'' by William Essex: a living lake of toxic waste that eats people and animals.
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[[folder:LiveActionTV]]
* Eva Mudlark of ''TheAquabatsSuperShow'' has made several of these out of anger from being treated as a lowly garbage collector.
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[[folder:TabletopRPG]]
* ''TabletopGame/CallOfCthulhu'' had a version of Creator/ClarkAshtonSmith's Abhoth (see above).
* ''TabletopGame/DungeonsAndDragons'' had a number of these, such as the Shambling Mound and the demon prince Juiblex.
** The nuckalavee from the Basic/Expert/etc D&D system lives in fouled water and kills small animals by its very proximity. A subversion in that it's not a product of pollution or a GreenAesop, and it looks like a skinned centaur with a FishPeople head rather than a pile of trash. Based on a monster from Scottish legend.
** A swamp that's tainted by ''magical'' pollution can create mudmen, which are ExactlyWhatItSaysOnTheTin. Not very intelligent, they try to drown anything that enters their swamp out of an instinctual urge, often destroying themselves in kamikaze attacks as they try to smother their foes.
** The ''{{Ravenloft}}'' Darklord Malus Scleris rules a domain that is the horror of unlimited pollution made real, and it is filled with these kind of monsters. Scleris is a pre-industrial version of a CorruptCorporateExecutive; his FreudianExcuse is that his father, a druid, only cared about his work, not about his son, so in return he hates Nature for taking his father away from him. His MO is control of horrible and disgusting diseases.
** Moander, a minor evil god from the ForgottenRealms, manifested in the form of a gargantuan crawling heap of rotting vegetation.
* In ''TabletopGame/{{Shadowrun}}'', city spirits usually manifest as piles of ordinary litter, unsightly but not all that icky. Toxic nature spirits manifest as contaminated water, smog, or ''really foul'' rubbish.
[[/folder]]

[[folder:VideoGames]]
* ''VideoGame/PokemonRedAndBlue'' has two Muck Monsters in Grimer and its evolved form, Muk. In the ''Anime/{{Pokemon}}'' anime, Ash's Muk was (initially) so smelly that it stank even after it had been captured in a Poké Ball. When he teleported it to Professor Oak's, it proceeded to engulf half the lab and reduced Professor Oak to ranting.
** Of course, said Muk really [[GentleGiant just wants a hug]].
** Koffing and Wheezing arguably count as this as well. They're based on pollution, but they're more inspired by smog that slime, although they do possess the ability to spit globs of slime.
** ''VideoGame/PokemonBlackAndWhite'' introduced the garbage Pokémon Trubbish and Garbodor. Their bodies pick up trash as they go, so they're ironically useful in keeping places clean.
* Master Belch and his upgraded form, Master Barf, from ''Videogame/{{Earthbound}}''. There are also the smaller monsters like "Pile of Puke" and "Stink Spirit".
* The Slag Golems enemy group in ''CityOfVillains''.
* ''Franchise/{{Digimon}}'' has Raremon, a crawling, blubbery pile of rotten flesh entangled with random cybernetics. It smells like dead fish and vomits as an attack. Raremon is one of several "garbage" type Digimon, monster who basically failed their evolution. Others include Sukamon, a living pile of feces, the slug-like Numemon, and Garbagemon, which even lives in a trash can.
* ''VideoGame/WildArms2'' had the boss "Drawdo," which resembled several dead fish melded together and attacked with every status effect in the game: http://www.youtube.com/watch?v=7gapGzA_fjw
* ''VideoGame/DemonsCrest'' on the SNES has the boss "Crawler," a huge mass of melted-looking flesh that takes on a semi-humanoid form after it swallows some bones. It can spawn zombie-like creatures from its body.
* The smoky Progg from ''VideoGame/{{Pikmin}}'' could count too as it is a horrifying crawling cloud of polllution which instantly kills any pikmin it touches. Not even unpicked ones are safe from its wrath.
* One of the bosses from ''VideoGame/ConkersBadFurDay'' was the Great Mighty Poo.
* ''VideoGame/WarcraftIII'' has some sludge-type creeps.
* The Amoeboids in the VideoGame/RatchetAndClank series are a kind of slime monster that walk in circles and says "Nein!". When hit, they split into two, half as small slime monsters (except for [[GoddamnedBats the smallest sort]], which just disappears). The biggest ones will split five times, meaning that you have to kill 63 slimes in total.
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[[folder:WebComics]]
* ''TheNonAdventuresOfWonderella'' has [[http://nonadventures.com/2008/08/09/the-bitter-end/ A variation]].
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[[folder:WebOriginal]]
* One of the monsters in [[http://armorgames.com/play/192/monster-basement Monster Basement]] actually is called "Mud Monster". It makes a brief reappearance in [[http://armorgames.com/play/2340/monster-basement-2 Monster Basement 2]].
[[/folder]]

[[folder:WesternAnimation]]
* Crud in ''WesternAnimation/TheNewAdventuresOfWinnieThePooh'' episode "Cleanliness Is Next To Impossible", a creature made from the filth under Christopher Robin's bed. He's defeated with a bar of soap.
* One episode of ''GoofTroop'' featured a CorruptCorporateExecutive who had become a MuckMonster due to overexposure to all the pollution created by his factory. Goofy returns him back to normal with a jar full of fresh air.
* Hexxus, the Tim Curry-voiced pollution-demon BigBad of ''{{Ferngully}}''.
* On several occasions the [[AppliedPhlebotinum mutagen]] on ''WesternAnimation/{{Teenage Mutant Ninja Turtles|1987}}'' spawned these creatures; they actually had names like "mud monsters" and "Mutagen Man." Basically, the theory that that this is what happens when the mutagen produces something that doesn't have the dignity of resembling a particular animal like a turtle. (And of course, the accidental workings of a mutatagen in RealLife are much more likely to produce a monstrosity like this than an anthropomorphic turtle....)
* In the ''{{Thundercats}}'' episode ''Mandora: The Evil Chaser'', one of Mandora's criminal prisoners is a Muck Monster known as The Living Ooze.
** Defeated with a powerful weapon of the ancients - [[spoiler:SOAP!]]
* ''TheTick'' animated series featured "The Filth," slimy sewer-dwelling creatures with, erm, tapered heads.
** And a variation with a snot-based clone of the Tick himself created by the being from the alternate dimension down the hall (34B, IIRC?). Not exactly a blob of muck, but it was made of snot/mucus and, while shaped like the tick, could squish itself into other shapes and use it's semi-gelatinous consistency to seep through cracks and around attacks and such.
* In ''WesternAnimation/LiloAndStitchTheSeries'', there's [[{{Mon}} experiment 505, Ploot]], who is designed to collect and absorb pollution and turn it into a toxic sludge to flood cities with. The more he collects, the bigger and grimier he gets.
* They were actually made of plain old mud, but in several episodes of the ''Disney/{{Aladdin}}'' regular series, the heroes ran afoul of the Al-Muddies, who were just as dangerous as any Muck Monster. These [[ElementalPowers elemental spirits]] were made of living mud, lived underground, and were carnivores known to prey on humans. Normal ones were feral, dimwitted, and brutish creatures who tended to attack in mobs; their Sultan, however, stands out, not just because of his titanic size, but via his incredible cunning and intelligence (not to mention being able to talk), and a fondness for cooking victims. (Even going so far as to call himself "a gourmet".)
[[/folder]]
[[folder:RealLife]]
* In the 1500s, the [[UsefulNotes/NativeAmericans Indians]] who met Europeans bathed regularly. In contrast, the Europeans had historically been in close contact to livestock and the attendant manure, and were averse to bathing. To the Indians, they would have seemed like this trope.
[[/folder]]
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