[[quoteright:314:[[Franchise/PiratesOfTheCaribbean http://static.tvtropes.org/pmwiki/pub/images/Pirat_6627.jpg]]]]
[[caption-width-right:314:Nobody expects the [[NinjaPirateZombieRobot skeletal pirate]] [[SuperNotDrowningSkills SEAL team]].]]

->''"My lord,"'' it was the master of the goblin blacksmiths, offering to build the king a new army, a mechanical army ''"seventy times seventy soldiers that can never tire, never know hunger or pain, and never be stopped."''
--> -- ''Film/HellboyIITheGoldenArmy''

This is a type of monster that is immune to starvation and dehydration, it may not even [[TheSleepless have to sleep]] or breathe. Much like the Energizer Bunny, it just keeps going and going and going. Perpetual Motion Monsters are either explicitly supernatural (e.g. TheUndead), a set of super advanced MechaMooks, or [[{{Magitek}} both.]]

Science savvy characters may [[DiscussedTrope discuss]] how implausible it is that the walking dead in a ZombieApocalypse, despite craving brains, can keep walking 24/7 for years or longer without any kind of sustenance. Compounded by that fact that though decayed they [[SlidingScaleOfUndeadRegeneration never actually rot enough to stop posing a threat.]] Frequently, TheProfessor / MadScientist will fear (or marvel) at [[JustThinkOfThePotential the potential]] these thermodynamic law-breaking monsters represent. This is the whole idea behind undead armies in any setting-- they are weak but fearless and while slow, they can march 24/7 with no supply lines, all while [[TheVirus assimilating the enemies' fallen]].

This is usually a JustifiedTrope for [[OurGhostsAreDifferent Ghosts]], DemBones, and {{Elemental Embodiment}}s since they aren't really biologically based, so they don't need traditional food sources. Although, they may need some ''other'' form of energy or material as a PowerSource [[GodsNeedPrayerBadly (like prayers]] or lighter fluid), thus [[AvertedTrope averting this trope.]] For MechaMooks and other technology based creatures they usually incorporate some near infinite PowerSource (or a means to tap into an external one) and some form of {{Regeneration}}.

It's worth noting that a character with the right type of {{Immortality}} who eats and drinks can still be a Perpetual Motion Monster -- or rather, a Perpetual Motion '''''Man''''' -- their form of immortality specifically preventing them from dying due to starvation and dehydration, though they probably [[ImmortalityHurts won't enjoy it]]... unless it's a case of them [[EatingOptional not actually needing to eat or drink]], and thus will not feel hunger or thirst in the first place. Such a character can make for a truly ImplacableMan -- nothing can keep him from his goal, not even the ravages of time!

For extra threat, the Perpetual Motion Monster is also usually [[WhoNeedsTheirWholeBody unaffected by dismemberment]] (except for the "annoyance" of a lost limb, though a [[AppendageAssimilation needle and thread can solve that]]). For extra ''extra'' threat, it's also a SuperPersistentPredator; since being a Perpetual Motion Monster means it doesn't actually need to eat [[EatingOptional except for the pleasure of it]], it can afford to go to the ends of the Earth in pursuit of that one tasty hero-sized morsel.

Compare AutomatonHorses (not the [[MechanicalHorse mechanical variety]]), where this is noted as one of the features that make fictional horses unusual. Compare ForgotToFeedTheMonster when this is averted.

See also YouCantKillWhatsAlreadyDead, where the undead just shrug off any injury for similar reasons as this trope.

Related to TheSleepless.

A SubTrope of TheNeedless.



[[folder:Anime and Manga]]
* The [[ArtificialHuman synthetic humans]] in ''Manga/{{Biomega}}'' come pretty darn close. They can live for months without food and for weeks without water and not lose efficiency.
* Androids 17 and 18 in ''Anime/DragonballZ'' are "infinite energy models" according to their creator, Dr. Gero. Androids 19 and 20 must absorb energy from people instead.
** Super-17 from ''Anime/DragonballGT'' [[MasterOfAll had the best of both worlds:]] He had the "infinite energy" power source, but could ''also'' drain power through his hands to increase his power level (and conveniently enough, weaken his enemies at the same time). Unsurprisingly it takes [[spoiler:a combination of FightingFromTheInside from 17 and [[IKnowYoureInThereSomewhereFight 18 pressuring him]] to even bring him down to the same level as the Z fighters.]]
* Alucard, a vampire, in ''Manga/{{Hellsing}}'' was sealed in the Hellsing estate for decades without blood and was still "alive". Granted, greatly weakened, and dessicated into a husk, but he still woke up when exposed to blood.
* [[OurVampiresAreDifferent Chiropterans]] in ''Anime/BloodPlus'' won't die from starvation, as happened to one imprisoned in a concrete block in Russia. It was emaciated but still awake and capable of killing.
* The [[InSeriesNickname eponymous]] warriors in ''Manga/{{Claymore}}'' do not need to eat or drink except in small doses. Though, when they awaken, they eat human flesh regularly, but can go without for a long time (several years), but it does weaken them...
* The Angels in ''Anime/NeonGenesisEvangelion'' are explicitly stated to have an infinite power source in their bodies: the S2 Organ. Therefore, while alive, they have no need for sustenance, rest, etc. and are effectively immortal, though they can still be killed if damaged enough.
* The [[OurGiantsAreDifferent Titans]] from ''Manga/AttackOnTitan''. While lack of sunlight and fatigue can slow them down, they do not age, sleep, or thirst and do not need the human flesh they eat.[[note]]They lack digestive tracts beyond their stomachs and just regurgitate when full.[[/note]] They even regenerate biomass instantly and out of nowhere while thriving.
* ''Manga/JoJosBizarreAdventure'':
** ''[[Manga/JoJosBizarreAdventureBattleTendency Battle Tendency]]'' has [[spoiler: [[BigBad Kars]] himself. Once he evolves into Ultimate Kars, there is simply no way for him to die. The only way Joseph could get rid of him was to shoot him out of orbit.]]
** ''[[Manga/JoJosBizarreAdventureVentoAureo Vento Aureo]]'' has the Stand "Notorious B.I.G.". It decomposes anything it touches, moves incredibly fast, and since it emerges when its user is dead, literally cannot die. [[spoiler: Its weakness is that it can't see, so it has to use motion detection to go towards the fastest-moving object within range. Bruno's gang "defeats" it by dropping it in the ocean, so it uselessly attacks waves for the rest of eternity.]]
* Most dragons in ''Manga/MissKobayashisDragonMaid'' require external sources of mana (like with Kanna plugging her tail into a power socket), but Tohru and Lucoa are both capable of generating their own. Other dragons are capable of using the mana that Tohru radiates, but Ilulu states that it tastes awful.

* ''Franchise/{{Superman}}'' foe Doomsday.
* TheIncredibleHulk cannot be stopped except by being calmed down by a close friend or loved one. Trying to subdue him by physical means only makes him angrier and his strength is proportional to his anger and has no upper limit.
* [[ComicBook/FantasticFour Reed Richards]] in ''ComicBook/MarvelZombies'' cites this trope as his justification for believing the zombie plague is the next step in evolution. He then proceeds to [[spoiler:infect the rest of the Fantastic Four.]] In this case, [[ReedRichardsIsUseless Reed Richards is]] [[EvilutionaryBiologist Genocidal]].
* [[ComicBook/DisneyDucksComicUniverse Scrooge McDuck]] once had an immortal zombie ([[PunnyName called Bombie]]) go after him for very long time, often walking nonstop across oceans, being frozen in ice for long time, and so on.
* The zombies in ''ComicBook/TheWalkingDead'' are Perpetual Motion Monsters, like most zombies. They technically don't last forever, as the characters have started to notice that more and more [[NotUsingTheZWord Walkers]] are extremely rotted, and on the verge of falling apart.
* For ''ComicBook/XMen'' foe Juggernaut, this is basically his power (mystical power in the comics, mutant power in the movie).
** Taken to an interesting new height in ''ComicBook/FearItself''. While possessed, he truly becomes unstoppable. At some point in the event, he calmly walks to San Francisco from a dozen miles away, while the X-Men try a [[CrazyPrepared bajillion]] plans to stop him. Teleporting him away does nothing, he just reappears instantly. Digging a giant trench in front of him does nothing, somehow he strolls calmly across thin air! The X-Men ultimately have to resort to [[spoiler:contacting the god that empowers Juggernaut and informing him that a second god has possessed his avatar. Cytorrak takes his power away from Juggernaut and transfers it to Colossus.]]
* Willy Pete from ''Comicbook/{{Empowered}}'' is an incredibly powerful fire elemental that eats superhuman flesh because he likes the taste, and because super-strong flesh is the only food that his mouth won't instantly incinerate. Being a fire elemental, he doesn't actually need to eat.
* ''ComicBook/JudgeDredd'': The Dark Judges are undead foes of Judge Dredd who have ruled their dimension for centuries as living dead. It's unlikely that their bodies even ''can'' decay on their own, as they are really being fuelled by their spirits' psychic power.
* ''ComicBook/PaperinikNewAdventures'' manages to provide an ''heroic'' example in Xadhoom: having effectively turned herself in a star in a humanoid body, her immense powers never run out, and to make things worse she can come back from ''complete disintegration''. She qualifies for the 'monster' part by being a HumanoidAbomination (something she's all too conscious of), and for being out to commit ''genocide'' on the [[HordeOfAlienLocusts Evronians]] for [[GenocideBackfire destroying her homeworld and her race]].
* [[Characters/GuardiansOfTheGalaxy Drax the Destroyer]] was originally created specifically to kill ComicBook/{{Thanos}}. His [[ArtificialHuman artificial body]] doesn't need to eat, drink, sleep, or breathe, doesn't age, is incredibly difficult to seriously injure, and if destroyed, regenerates from his own remains (or from the soil where he was originally created, if there isn't enough of his former body left). Unfortunately, in the decades since Drax's original creation, Thanos has had [[PowerCreepPowerSeep several power-ups]], reducing Drax from his oringal "grim avenger" status to a perpetual ''annoyance'' (for Thanos, not his [[MookHorrorShow minions]]). These days, he doesn't even rank among the Mad Titan's top ten enemies (though he did [[CrowningMomentOfAwesome manage to score the coup de grâce]] during {{ComicBook/Annihilation}}).

[[folder:Fan Works]]
* [[LivingShadow Enjin]] works this way in ''FanFic/TheBridge''. Being composed of solid dark magic, it need not rest, eat, or drink to continue pursuit of its quarry. [[spoiler:It's only weakness is that if separated from its master Bagan for long periods of time, its body will start to deteriorate.]]
* Jovian and Jacqueline Kikion of ''FanFic/RosarioVampireBrightestDarkness'' are this, thanks to being enhanced with Alucard's blood. They have no known limit to their power levels, and can fight non-stop without ever tiring.

* The eponymous army in ''Film/HellboyIITheGoldenArmy'' is a positively inhuman combination of perpetual motion monster, TheJuggernaut, and ''[[PullingThemselvesTogether regenerating]].'' It was an ancient weapon GoneHorriblyRight to the point the elf king who commissioned it sued for peace after it massacred a human army.
* The monster from the movie version of ''Film/PeterBenchleysCreature'' survived locked in a cage on the sea floor without any food or room to move for decades without any debilitating effects. The book version averts this by having it stalk out of its cage in a deep sea trench ever so occasionally.
* The [[Film/TheTerminator original]] ''Franchise/{{Terminator}}'' movie made the eponymous cyborg sound like this trope, until the [[Film/Terminator2JudgmentDay second film]] subverted it by revealing that his power cell would eventually run out....[[DownplayedTrope after 120 years.]]
* In the ''Film/{{Underworld}}'' film series, the first Lycan William Corvus was sealed in a tomb for 600 years. Once he's out of his coffin, he's at full strength. He clearly wasn't in suspended animation.
* Referenced in ''Film/PiratesOfTheCaribbeanTheCurseOfTheBlackPearl'', when undead Barbossa banters with an equally-undead Jack that they could keep fighting their duel for eternity.
* The monster from ''Film/ItFollows'' may not move fast, but it will never stop chasing whoever has the curse until they're dead. Then it goes after the ''last'' person who had the curse. It doesn't help that It is able to [[ParanoiaFuel take on the appearance of anyone]].

* In Creator/RobertEHoward's ''Literature/ConanTheBarbarian'' story ''Literature/BlackColossus'' there's a giant venomous python which slithers out of a ''3000 years old tomb'' and is still lively and in top shape.
* Similarly, the basilisk in ''Literature/HarryPotterAndTheChamberOfSecrets'' had apparently been stuck there since the founding of the school, waiting for its master's heir to come and release it.
* In ''Literature/TheLordOfTheRings'':
** The Watcher in the Water is a massive squid-like beast living in a lake just outside Moria. It had been driven from the deeps of Moria into the flooded valley as a guardian and to trap the dwarves inside Moria. A creature that big just hanging around in caves needs to have SOME of this going on though.
** The Balrog in Moria isn't slowed down at all by being entombed underground for millennia, thanks to being an immortal angelic spirit before its [[FallenAngel corruption]] by Morgoth.
* The cauldron-born from ''Literature/TheChroniclesOfPrydain'' are deathless zombies animated by the Black Cauldron. They do not eat, sleep, breathe, or get tired, and they feel no pain.
* In ''Literature/TheZombieSurvivalGuide'' zombies are explained by the virus which creates them replacing their mitochondria and taking over respiratory functions so they no longer need to eat or breathe ([[HandWave ...somehow]]) and slightly more plausibly, delaying decomposition by protecting the body from rotting as the immune system would have. The later part of the trope is also averted, since zombies do rot away after a few years, unless they're in arid environments or end up being frozen.
* Not "monsters" per se, but ''Literature/{{Discworld}}'' {{Golem}}s just keep going and going and going and going. They're used for menial, tedious labor typically, since they don't have to sleep and, for the most part, enjoy it as much as they can enjoy anything. They even use this as a form of passive-aggressive protest via LiteralGenie; they're smart enough to take initiative and can read the intent behind orders, but if you mistreat them, they're liable to fight back by doing ''exactly'' what you say, constantly, until someone figures it out and tells them to stop. This can mean that the golem you asked to "pump some water" doesn't stop until your shop's street is partly underwater.
** A more traditional version, also a golem, is Mr. Pump in ''Discworld/GoingPostal''. As Moist's parole officer, it's explained that even though he can only walk while Moist can run, get a horse, or a cart, he will never tire, and never stop until he catches up to him. After one demonstration of this, Moist gives up on trying to run away.
-->You can hide, but you can't run!
* In Brandon Sanderson's ''Literature/{{Warbreaker}}'', there are two. The first and most well-known are the Lifeless, an army of ImplacableMan zombies who do not need to rest or eat or drink or breathe. They obey any command given to them by anyone with the proper code-words. Whoever controls the army of Lifeless has control, more or less, over the kingdom.
** Much worse, as it turned out, were the Phantoms of Kalad -- like the Lifeless, but ''made of stone'' and thus damn near impossible to kill.
* In ''[[Literature/JohnCarterOfMars The Synthetic Men of Mars]]'', a malfunction at an already imperfectly working cloning facility produces a constantly growing mutant entity that consists of a huge blob of human flesh and random body parts. It's stated that [[ItsTheOnlyWayToBeSure if it hadn't been]] [[KillItWithFire fire-bombed]] from above until there was nothing left, it could have grown forever by ''eating itself''. Just think of the potential applications of something like that on a starving planet.
* The zombies in ''Literature/DiarioDeUnZombi'', minus some very gradual wear and tear.
* In ''Literature/MortalEngines'', the cyborg zombie Stalkers are explicitly stated to draw energy from the environment somehow, and are otherwise capable of functioning without needing to eat or recharge or refuel for an indefinite amount of time. And the oldest Stalkers, the ones made with LostTechnology, can't even ''die''. They just go dormant, ready to fight again as soon as they're repaired and reactivated.
** Lampshaded at one point; when a stalker expert is asked by Fever Crumb(who is rather confused about how Stalkers are possible) how they work, she responds with "molecular clockwork". Fever instantly identifies it as an In-Universe HandWave.
* ''"That is not dead which can eternal lie..."'' '''Lots''' of examples in the works of Creator/HPLovecraft.
* In ''Literature/FirebirdLackey'', the dragon and the "dolls" in the Katschei's palace are implied to be mechanical in nature, possibly even robots that obey short logical orders. More than that, neither need sleep or fuel, though the dolls do seem to "tire" and need a day to recharge.
* In the ''Literature/LeftBehind'' series, one of the perks Nicolae Carpathia gets from being possessed by Satan is that he no longer needs to sleep, drink or eat; the evil power of Satan providing all of his needs. When Satan leaves his body, all of this is immediately canceled and Nicolae becomes a shriveled, emaciated barely-living cadaver.
* The undead (both [[OurLichesAreDifferent lazar]] and [[OurZombiesAreDifferent regular ones]]) from ''Literature/TheDeathGateCycle'' don't get tired, don't need to eat, drink, or breathe, can ignore most injuries that don't directly impair their functioning and can repair even those with a necromancer's help (lazar who were necromancers can repair ''themselves'' almost instantaneously, making them [[ImplacableMan all but unstoppable]]). As such, if they want you dead, they can and will keep coming until you ''are''. The lazar are also an unusually literal example of this trope, as their soul wants to escape into the afterlife but cannot, and its attempts to do so compel the body to wander or, if prevented from doing so (such as by being trapped in a small room) to incessantly pace. These creatures are ''literally'' in perpetual motion.

[[folder:Live-Action TV]]
* ''Series/BuffyTheVampireSlayer'': Adam is one, thanks to his Uranium-235 core.
* The Jem'Hadar in ''Series/StarTrekDeepSpaceNine'' are genetically engineered so that the only source of nourishment they need is [[{{Phlebotinum}} Ketracel White]], a narcotic which keeps them loyal and without which they die after going violently insane. On top of that, they are conditioned to be unwaveringly loyal (though this has proven to be slightly unreliable, hence the White as a secondary measure). And the occasional Jem'Hadar has a mutation causing them to not even need the White, meaning that nothing other than violent death can stop them.

* The serpent that guarded the GoldenFleece, which never slept or left the tree except when drugged.

[[folder:Tabletop Games]]
* In ''TabletopGame/DungeonsAndDragons'':
** Constructs such as golems have no physical needs. The Warforged MechanicalLifeforms in the ''TabletopGame/{{Eberron}}'' setting are a partial example in that they don't need nourishment but do need a few hours of complete inactivity each day.
** Undead don't need food or rest, though some types have {{Horror Hunger}}s that they need to indulge.
** Outsiders like angels and devils don't need food or sleep, although they might enjoy them anyway.
** Partially the case with the mantis-like desert-dwelling thri-kreen, but they do not need rest, and can function constantly. But they do need to eat and breathe.
** Elves do not sleep (in fact they ''cannot'' sleep - spells that magically put creatures to sleep do not work on them) and suffer no ill effects for it. However they are stated to need roughly 4 hours of trance-like meditation every day.
* Artifacts in ''TabletopGame/MagicTheGathering'' usually have this quality, as do a lot of undead. Phyrexians in particular are prone to combining the two.
* ''TabletopGame/RoleMaster'' has the Black Reaper, an extremely powerful demon that is commonly used to guard items or places. Once disturbed, it will never stop pursuing the offender until he or she is dead. It is immortal and doesn't need food or air, and is never bored. When it follows it's soon-to-be victim, it will just walk underwater through oceans or use it's magic axe to tunnel through all but the hardest material.
* Vampires in ''TabletopGame/VampireTheRequiem'' need blood to awaken in the evening but not to function normally. In theory, one could be perfectly happy in a sun-proof room for as long as it can force itself to stay awake at dawn.
** One particular covenant of vampires, the Ordo Dracul, have a way to increase the amount of sustenance from the blood they drink, increasing to 1.5X what they get when they drink from humans and ''doubling'' blood drunk from vampires. Two such vampires can (canonically!) make infinite blood by feeding off of each other, becoming this trope. The downside is it leads to blood addiction and/or MoreThanMindControl and/or FoodChainOfEvil kicking in. So to keep its members from trying this the elders in the covenant seal all such vampires in steel boxes which they dump into the ocean, whereupon said vampires spend ''eternity'' feeding from each other. [[note]]Unless one eats the other, at which point it's an eternity of starvation.[[/note]]
* In the ''TabletopGame/LegendSystem'', the feat By Will Sustained can produce this or TheDeterminator depending on whether it's taken by a monster or a player character. At level ten breathing and sleeping become optional.

[[folder:Video Games]]
* Necromorphs in ''Franchise/DeadSpace'' neither need to eat, drink, sleep, nor breathe. Have fun! The Hunter has the added benefit of infinite biomass to regrow lost limbs, making it almost unstoppable.
* The [[ImplacableMan Dahaka]] from ''VideoGame/PrinceOfPersiaWarriorWithin'' fits the role.
* ''VideoGame/DwarfFortress'' actually has tags for these including [NOEXERT], [NO_EAT], [NO_DRINK], and [NO_SLEEP]. In-organic creatures like bronze colossi and iron men don't need any, while Goblins just don't need to eat or drink (due to the idea that all of them should die a violent death).
* Corprus infectees in ''[[VideoGame/TheElderScrollsIIIMorrowind Morrowind]]'' suffer massive, [[BodyHorror uncontrolled muscle growth]], to the point where they can apparently survive by cutting off their own tumors and eating them.
* Alex Mercer and James Heller in the ''{{VideoGame/Prototype}}'' games are stated to have no need for food or rest and only [[IAmAHumanitarian absorb]] people to heal major wounds.
* [[LivingShip Reapers]] in ''Franchise/MassEffect'' can operate a seemingly infinite amount of time without the resupplying other ships need constantly. This gives them a rather considerable advantage against everyone else. It's generally assumed that whatever it is they're using for fuel, it's based in [[SufficientlyAdvancedTechnology technology beyond the understanding of their targets]].
* ''VideoGame/Left4Dead'' hangs a dramatic lampshade regarding the [[TechnicallyLivingZombie Infected]]. One of the pieces of graffiti on a safe room reads:
--> ''They don't eat, they don't sleep, WHAT KEEPS THEM GOING?''
* Robots in the ''Franchise/{{Fallout}}'' games. By Fallout 4 it's been more than 200 years since the war that destroyed civilization, but you'll still find plenty of Mr Handies and Securitrons operating at full power despite a lack of access to any apparent fuel sources. Ghouls, despite being alive, are occasionally treated this way as well: there are multiple instances in the game where you'll encounter feral ghouls that have been trapped inside a room without a food source since the bombs fell, and they're still very active.

* The Uncroaked/decrypted in ''{{Webcomic/Erfworld}}'' have zero upkeep.
** Interestingly, the latter still eat and drink, and are provided with what they need as if they had their usual upkeep cost (in the textual interludes, Parson tried Decrypted archon rations). ''Something'' outside the known forces of the world is evidently picking up the tab.
* After Act 5 Act 2 of ''Webcomic/{{Homestuck}}'', [[spoiler:the Peregrine Mendicant]] spends 3 years chasing [[spoiler:Bec Noir]] across the chasm of space between worlds without either ever stopping, save for a very brief interlude.
* The ''WebComic/StandStillStaySilent'' [[OurZombiesAreDifferent variant of zombies]] has living beings that were infected ''90 years ago'' still running around.

[[folder:Web Originals]]
* The wooden soldiers from ''Doraleous and Associates''. Though they can be disabled with enough damage, their master need only command them to rise again and they will.
* The whole premise of the Creator/RoosterTeeth Animated Adventure [[https://www.youtube.com/watch?v=HINYhLtaaxc The Snail Assassin]]
[[folder:Western Animation]]
* In ''WesternAnimation/StevenUniverse'', The gem monsters, much like the gems themselves, require no sustenance to continuously project their HardLight bodies and can live forever provided their gems are not shattered. Because of this, the Crystal Gems have to bubble their gems to keep them in suspended animation when they 'poof' them.

[[folder:Real life]]
* The politician Vermin Supreme [[https://www.youtube.com/watch?v=4d_FvgQ1csE&=&t=3m34s proposed using zombies]] as a ''power source'' in his 2012 campaign to reduce America's dependency on foreign oil; by placing zombies in a giant turbine and dangling some brains in front of them to make them push the blades, they can become a PerpetualMotionMachine.