Some monsters are Immune to Bullets; some are indestructible, barring the obvious Achilles' Heel; some smother their opponents in hordes of easily-replaceable drones; some just keep coming back no matter how thorough their demise seems... and then there's some that simply cannot be fought at all.
A native of the horror genre and its imitations in other genres, this breed of foe cannot be opposed in any reasonable way, lacking weaknesses, exploitable character flaws, or even opportunities to counterattack. The reasons for this vary: maybe it's because they're simply too powerful to be harmed in any way; perhaps they never give their victims a chance to retaliate; maybe its because they're effectively intangible. In some cases, it's because you're too weak to fight them and probably never will be strong enough to do any real damage.
Whatever the case, fighting the monsters fast approaching is out of the question: they can't be hurt, harmed, suppressed or negotiated with, and killing them is damn near impossible.
In other words, it's time to Run or Die.
Though hardly unique to the medium, this trope has flourished in video games. A popular way to enforce the survival part in many Survival Horror video games is to leave the player with no chance to survive (or make their time) in battle against the monsters; the moment the assailant catches up with them, it's game over, so the player's only option is to turn tail and run away as fast as possible. In many instances of this, the player will also be obliged to find a hiding place, turning the game into a tense mixture of stealthily creeping from bolthole to bolthole and desperately fleeing the unstoppable pursuer.
The modern prevalence of this trope can be seen as the antithesis of modern Action Horror games, which are oft considered to be little more than spooky shooting galleries rather than true "horror" games by purists. In this case, all the enemies are Invincible Minor Minions by default, and cannot be harmed in any way; in cases that allow these foes to demonstrate their invincibility should the player be brave enough to stick around and battle, a Hopeless Boss Fight may ensue.
Important Note: to qualify for this trope, the monster or villain has to be played for horror; a simple Hopeless Boss Fight in an action game does not count.
Astute readers may note that this trope has significant overlap with Invincible Villain. However, where the Invincible Villain cannot be defeated by anything including running away and always ends the story victorious, the Invincible Boogeymen are only impossible to defeat in confrontations; the latter can still be escaped or hidden from provided you're fast enough, and may even be defeated through the use of some special loophole in their invulnerability. Said weakness won't be discovered until the very end of the encounter, if not the very end of the story itself. Of course, don't count on this being a guarantee in video games; you're better off just running and never looking back.
- Vento Aureo: Carne's Stand, Notorious B.I.G, is unique in many respects: it only activates after Carne's death and thus, the standard strategy of "knocking out/killing the Stand user to stop the Stand" is useless. It's a Blob Monster that consumes everything in its path, is nigh-indestructible — having pieces of it chopped off will just make the pieces sentient — and it will chase after sufficiently speedy thing nearby, and it can move really fast. Its only weakness is that it only acts in primal instinct, so it can be fooled in various ways; the protagonists only get rid of it after it hijacks the plane they're flying in (by partly consuming it) and they escape in midair, while the plane's failing engine causes it to fall towards the ocean. Even then, it's still alive, thoroughly confused with the ever-moving ocean currents (which trigger its instinct); it's said that the ocean it fell in becomes a scary place, with multiple ship sinking incidents caused by the still-living Stand.
- Big Finish Doctor Who:
- The Child in "The Holy Terror". An all-powerful Enfant Terrible, nothing in the castle can kill it or even slow it down; the Doctor can't fight it, dissuade it or technobabble it away. By the end of the story, the heroes are reduced to hiding in the throne room while the Child massacres its way through the populace, knowing that there's nothing they can do but wait until it comes after them. As it turns out, as the author of this scenario, Eugene can destroy the Child, but that just results in the entire Vicious Cycle repeating itself and the damn thing reappearing later anyway. The only thing Eugene can do to escape is let the Child kill him, ending his suffering and deleting the Child from existence.
- Death in "Master". Both the Doctor and the Master find out the hard way that there's no way of opposing her in any way, shape or form: attempts to talk her down only end with the recipient being Mind Raped; the one effort to actually attack her ends before it can even begin. In the end, the only sane thing to do is run like hell, all while pursued by nightmarish stimuli across the house. The story concludes on a Bad Guy Wins note, with the Doctor in indentured servitude to Death and the Master still trapped in her schemes.
- Immortal Hulk. Given his enormous strength and healing factor, you could argue that the Hulk was already this before, but since this series started, it has been revealed that while Bruce Banner can die, the Hulk will always rise up when the night falls. And given his new "Devil Hulk" persona seems to enjoy sadistically punishing others, he's more of a horror monster than ever. The Bad Future sequence reveals that once he's fully possessed by the One Below All, the Hulk becomes this to the entire universe.
- Uncanny X-Men: Unless you're a strong mutant with a team of other strong mutants backing you up, good luck trying to fight Magneto. Never mind that he's Immune to Bullets, never mind that he can throw up Deflector Shields to protect himself from other attacks, the guy controls the fundamental forces of the universe. His dignified persona prevents him from sinking to down-and-dirty movie monster levels, but during his solo series the Marauders had a terrifying encounter with him that showed readers just how horrifying Magneto can be when he isn't fighting the X-Men and no longer feels any need to practice restraint.
- X-Men: The Unstoppable Juggernaut got his name for a reason. Aside from a select few immensely powerful individuals, he is impervious to physical harm. The one way to put a halt to his rampage is to get his helmet off and let the resident telepath subdue him or teleport him somewhere he cant hurt anyone. Even then hes managed to come up with counter measures to these weaknesses over the years.
- Art the Clown of All Hallows' Eve and Terrifier. An Ambiguous Humanoid Abomination, stopping him seems almost impossible and he may actually be capable of teleportation. In the finale of Terrifier, he escapes capture by shooting himself in the head... only to come back to life in the morgue not long afterwards.
- The Babadook may eventually be repelled with screaming, but it is also the Anthropomorphic Personification of depression and connected mental illnesses and it's utterly inescapable as a result — the best Amelia can do is accept that the damned thing is going to haunt her basement from now on and if she ever slips up, all of the horror she had to endure is going to start all over again.
- As an Evil Counterpart of Superman, Brandon Breyer of Brightburn is just as impervious to bullets as good old Kal-El. The only thing that can hurt him is metal from his spaceship, and given that he's got Super Speed, good luck trying to stab him with it. And since he went so far as to drop a plane on said spaceship at the end, it's very likely that it has been destroyed.
- In Friday the 13th, Jason Voorhees is practically nigh unstoppable and will kill everything in his path once he sets his eyes on a target. The only defense is slowing him down or running. The lion's share of the movies is spent trying to find some way of putting him down for good, and success is usually only found at the very end of each installment. While he can die, he never stays dead, as a subsequent film will end up reviving him somehow so he can spread further terror.
- Final Destination sees Death hunting those who escaped it through prophetic visions they experienced. Death is both all-powerful and eternal, meaning it's not really a fair fight so much as a sadistic boy squashing a bunch of helpless ants. This is because death itself is inevitable.
- The entity from It Follows. It always knows where its targets are, it can't be seen by anyone except its future victims, and nothing can stop its pursuit: sooner or later, it always catches up. The only way to escape is to have sex with someone and spread the curse to them, or spend the rest of your life on the run. The ending reveals that it's impossible to kill as well.
- Freddy Kreuger from A Nightmare on Elm Street is more or less this trope distilled to its core. He's literally a boogeyman, having transcended the boundaries of life and death to haunt the world of dreams, and in that world he has the Imagination-Based Superpower writ large. If he wasn't a Sadist and a Combat Sadomasochist he'd probably be completely invincible; as it is his personality disorders inevitably allow the Final Girl to (temporarily) slay him after he's inevitably killed off the rest of the cast.
- Kayako of Ju On is a ghost with the goal of killing everything that gets her curse and nothing can be done about it — you can't run, you can't hide, you can't appease her, and you surely can't exorcise her. One film even has her being deliberate summoned by the victim of the film in an act of insane desperation in the hopes that she will fight another killer ghost and hopefully they will destroy each other. That film is Sadako Vs. Kayako — look below on the Ringu bullet point to see how much it didn't worked.
- In The Matrix, Agents are basically invincible killing machines who have Super Strength, Super Speed and the ability to Body Surf. All Red Pills are advised to Run or Die as any encounter with them is practically suicide unless you're The One like Neo. The kicker is even if somehow you manage to kill an Agent's current body, they'll just jump to another body good as new and continue their pursuit.
- The Tall Man from Phantasm movies is an Eldritch Abomination inhabiting the human corpse of an old man who journeyed into his dimension one day. He's super-strong, impervious to almost anything, can send deadly flying spheres against his targets, and even completely disintegrating him just means an identical Tall Man emerges from the portal.
- Samara of The Ring is utterly unstoppable: once you've seen the cursed tape, your death is totally assured. When she finally appears in person to claim a victim, she cannot be fought in any way. Even finding her mortal remains and putting them to rest doesn't stop her. The only way to escape Samara once and for all is by getting someone else to watch the tape, transferring the curse to them instead.
- Sadako from the Ringu movies is even worse: she eventually evolves her curse into a literal disease, an airborne virus that is incurable and subjects it's victims to die the same way that those tho saw the tape did. Even tossing another Invincible Boogeyman at her doesn't works — the film Sadako vs. Kayako ends with both homicidal ghosts undergoing a Fusion Dance and spreading a combined version of their respective modus operandi onto the world.
- In Terminator most Terminators are Implacable Men who can sustain heavy damage and keep on killing, but special mention goes to the liquid metal T-1000 Terminator from Terminator 2 which is virtually indestructible as its Blob Monster construct means almost no damage done to it is permanent and it'll just reseal holes blown in its torso or head.
- In X-Men: Days of Future Past, these versions of the Sentinels are truly Nigh-Invulnerable juggernauts who cannot be beaten in a fight by any means. The only way the surviving mutants have managed to stay alive is by running and hiding, then going back in time to warn their past selves to relocate whenever their base gets compromised. The only permanent way to defeat them is to go back decades in time and prevent their existence.
- In the John Connolly short story "Mr Pettinger's Daemon," the eponymous monster is beyond being fought in any way by the protagonist and it's not even certain if it can be harmed much less killed. All our hero can do is run like hell and collapse the supports holding up the tunnel the daemon is just about to escape through. Even this isn't enough to kill it, unfortunately, for the story ends with the protagonist revealing that he can still hear it slowly digging its way to the surface...
- Par for the course in the works of H. P. Lovecraft and the Cthulhu Mythos: more often than not, the Eldritch Abominations encountered over the course of the stories cannot be fought or killed in any way, and the main characters usually have no choice but to run for their lives. The nearest thing to a fight in humanity's favor was when Cthulhu himself got his head split open by the prow of a ship — and even that ended with Cthulhu easily regenerating.
- When first introduced, The Beast of Lev Grossmann's The Magicians is a pretty obvious case of this: when accidentally summoned, he freezes everyone in place as he prowls around the classroom, manages to prevent an entire faculty of trained magicians from entering the classroom to rescue the students, and when one of the students tries to retaliate, the Beast just eats her alive - while Quentin and Alice can only look on in paralyzed horror. Nobody ever gets a chance to fight back, and it's made clear they wouldn't have been able to do much anyway. By the time they meet again, Alice and her fellow Physical Kids have graduated into fully-fledged magicians and actually manage to put up a serious fight against the Beast - but he's still virtually invincible until Alice makes use of a Deadly Upgrade.
- In Robert Sheckley's "Ghost V", the heroes visit a planet with an atmosphere full of a drug bringing out hallucinations of their childhood bogeymen, potentially lethal due to Your Mind Makes It Real. They take out a couple of monsters with a magic word and a water pistol, but the last bogeyman is absolutely invincible. It's also capable of getting past any lock and door. But not through a Security Blanket, fortunately.
- Doctor Who:
- The eponymous child in "The Empty Child" and "The Doctor Dances". On top of having a host of powers that make him effectively unstoppable, any physical contact with him will only turn any attackers into more gas-masked zombies; plus, he might not be inclined to run after his targets, but once he's gotten interested in something, he will not stop following you. As such, the only sensible move is to either run or hide. He's stopped when he finds his real mother, allowing the nanomachines infesting him to correct their original mistake and restore him to normal.
- The Weeping Angels, especially in their original appearance in "Blink", when they're up against ordinary humans. The Angels are not only indestructible in their stone state, but when nobody's looking at them, they move too quickly to be attacked; all it takes is one blink at the wrong time, and you're dead. In their first outing, they're defeated when they're tricked into looking at each other, freezing them in place. They are not completely indestructible as another instance has them be frozen... and unable to escape being sucked into a black hole.
- The Vashta Nerada from "Silence in the Library" and "Forest of the Dead". They are microscopic organisms that appear as Living Shadowes when gathering in swarms, described as "piranhas of the air" — and their diet includes humans. They seem only marginally Weakened by the Light, as it slows them down rather than actually harming or stopping them; worse still, they can also turn characters that they've already devoured into vessels by inhabiting their space suits, allowing them to walk in the light. When asked how to deal with the Vashta Nerada, the Doctor lampshades this trope by listing off weaknesses of various monsters, before adding "Vashta Nerada... run. Just run." In the end, they aren't really defeated, only intimidated into delaying their advance by the Doctor's own feared reputation so he has enough time to teleport everyone off the planet.
- The Flood from "The Waters of Mars": essentially a waterborne disease capable of infecting any biological lifeform so long as they contain water, its hosts are swiftly converted into zombielike monsters that continue the spread of the virus. While Flood hosts can be slowed down, nothing in the long run can stop them — as the Doctor puts it, "water always wins". One by one the crew of "Bowie Base One" on Mars become infected, as only one drop of water is all that takes to convert someone. In the end the only way to dispatch them is by activating the Self-Destruct Mechanism on the base while the Doctor evacuates the survivors via TARDIS.
- House quickly becomes one of these in "The Doctor's Wife" once he transfers his mind into the TARDIS. Not only is it impossible to harm him since his body is now a pan-dimensional time machine, but he's also capable of using his control over the TARDIS's internal systems to Mind Rape Amy and Rory in particularly cruel ways. For good measure, during his scenes, the tone of the episode takes a sharp turn away from drama and comedy and into flat-out horror. The only way to defeat him is to sneak the TARDIS' current body on board and allow her to force House out of the system.
- The Whisper Men, Mooks of the Great Intelligence appearing in "The Name of the Doctor". As they're completely intangible, nothing the heroes do can hurt or slow them down, and they very nearly kill the Doctor's friends over the course of the episode. In fact, they're never defeated at all: they only stop when the Great Intelligence achieves his goals, causing them to disappear with their purpose fulfilled.
- The Foretold of "Mummy on the Orient Express". Effectively intangible, its touch kills instantly, and nobody else can see it except for its victims. As with most monsters on this show, it's Immune to Bullets — but also to all potential technobabble solutions. Once you're targeted, you have exactly sixty-six seconds to live before it catches up with you, amping up the horror and tension significantly. The only way to stop it is to surrender to it.
- "Flatline" features two-dimensional beings which The Doctor dubs "the Boneless". They will kill anyone they come across by turning them 2D as well and dissecting them. Due to the bizarre nature of their anatomy, they cannot be fought at all and the only defence against them is to run. The only way the Doctor gets rid of them is by sending them back to their own plane of existence — and only once he's gotten the TARDIS working again.
- The Veil in "Heaven Sent". A childhood nightmare empowered with a lethal touch, it can't be harmed, persuaded, intimidated, outsmarted, or technobabbled away — meaning that all the solutions that the Doctor usually resorts to are officially useless. The Doctor has only two options: confess his deepest secrets or run for his life. And though the Veil doesn't move very fast, it's impossible to escape the Castle through conventional methods, and the Doctor has to stop long enough to eat or sleep — meaning that the Veil will catch up sooner or later. It's defeated by the Doctor finally breaking through the wall between him and the exit, causing the Veil to collapse into inert junk.
- The Haunting of Hill House ultimately reveals that the eponymous house is one of these; not only is its power just about impossible to resist, but the building is seemingly indestructible. Trying to burn the place down only results in the fire instantly extinguishing itself. Only the intervention of Nell's ghost saves her siblings from the Red Room, and even then she can't do much more than keep them safe until the family's out of the building. In the end, the only thing you can do is remain as far away from it as possible, and never visit after nightfall.
- House of Anubis has the season 2 villain, Senkhara. Compared to the other villains, she's much more dangerous and unstoppable, being a ghost that can enter dreams, lay curses, and kill people with her magic, while everyone else is just a human with shady intentions and ulterior motives. The Sibuna gang are forced to work for her and do as she says, and are unable to stop her or escape her control. The only thing that defeats her is being inside the mask when Rufus puts it on, which causes them to both be dragged into the underworld thanks to Rufus's evil nature, rather than anything the students could've done.
- Merlin features the Dorocha a Monster of the Week in "Darkest Hour". Their name literally translates to "Shadow people" and are malevolent spirits of the dead with the appearance of gaseous flying skulls and whereby they come into contact with a person, they are almost always instantly dead (Merlin being the only exception due to his magic). Unlike most monsters on the show, they cannot be fought in any way, being completely unaffected by blades and even magic. The only defense against them is that they are Weakened by the Light, but even this only repels them and doesn't kill them. The only way of stopping them is by one person being chosen as a sacrifice to restore the natural order that released them, to which both Arthur and Merlin attempt to, but ultimately it is Lancelot who performs the deed.
- The End of the World:
- Cthulhu of "Wrath of the Gods". As with his original counterpart, nothing can stop him; as you're playing a lone everyman caught up in the apocalypse, you don't have access to the kind of weapons that can even mildly inconvenience the chief of the Great Old Ones, so all you can do is run like hell and avoid looking at him.
- The nanites of "Revolt of the Machines". Most of the time, they're too small to be seen until they start eating something — or someone — leaving you effectively helpless; when a nanoswarm gathers in large enough numbers to be seen by the naked eye, nothing in your arsenal can hurt them. All you can do is put an ocean between you and the infestation, and that won't work for long. The post-apocalypse scenario features 80% of the human race being wiped out, the survivors either sheltering in Arctic bases or living as nomads just out of the nanoswarm's reach.
- The Xenomorph in Alien: Isolation. It's immune to all weapons, trying to tackle it up close is suicide, and the only item that's of any use against it is a flamethrower — and that's only because it's afraid of fire. More often than not, the safest option is to hide in a locker or run for your life in as quiet a manner as possible.
- Almost every monster in Amnesia: The Dark Descent is one of these, but they do give up and go away if the player hides themselves well enough. Just looking at them is enough to drive the player character mad, and as soon as one catches sight of you, you're practically dead. However, the most prominent example is the Shadow, as unlike other monsters which you can hide from or distract, the Shadow will find you wherever you go and is truly unstoppable. It will NEVER stop chasing you until it decides otherwise.
- Divinity: Original Sin has the Death Knights, who hit like a truck and are perfectly unkillable when you first run into them in the Luculla Mines (a unique status effect renders them impervious to any and all HP loss and there are no insta-kill abilities in the game). The only way to progress is to sneak around or to teleport, and if you aggro them, run like hell (thankfully, they are also quite slow on their feet). Later on, this is subverted when you discover a way to disable their invulnerability, after which they become a regular, if tough enemies.
- The eponymous character and his friends in Five Nights at Freddy's. Due to a cascade of horrible ideas by the pizza company, you're basically stuck playing security guard to a bunch of animatronic performers who want to fatally jam you into a Freddy Fazbear suit; you can't fight them and you can't escape until 6 AM, so all you can do is lock the doors if any of them get too close and hope that power doesn't run out.
- In MediEvil, the overwhelming majority of the monsters can be defeated no matter how tough they seem at first, befitting the horror-comedy atmosphere. However, in Scarecrow Fields, there's something living in the cornfield that cannot be fought, cannot be killed and cannot even be seen. If you stray into the cornfield and don't leave immediately, you'll be rewarded with an ominous hissing noise as something large rushes through the corn towards you, and then you will instantly lose a life. That's it.
- The SA-X of Metroid Fusion is a copy of Samus at her full strength, and as such can kill her in a few hits, freeze her in place and generally forces the player to run when its telltale footsteps show up.
- Daniel Remar's Metrojd features this: the crux of the game is spent jumping across the map as an unseen monster howls in the distance, shaking the area as it gets steadily closer. When it does show up, it can't be killed, hurt or even attacked; getting too close to its jaws will result in game over. All you can do is run.
- The Hairshreaker in The Missing JJ Mac Field And The Island Of Memories occasionally shows up, and shifts the gameplay from solving puzzles to advance to simply running and clearing obstacles as quickly as possible. Later inverted; J.J turns into the Hairshrieker herself, and has to slay Emily in a boss battle (representing the fact that it represents her own self loathing and suicide ideation, and how it hurts other people).
- In Mother 3, getting too close to the Ultimate Chimera results in an automatic Game Over, with the usual battle screen not even appearing for a moment.
- The Outlast franchise leaves the player at the mercy of opponents who cannot be fought, only evaded; as the first game reminds you, you're not a fighter — and the fact that many of your opponents are unnaturally strong or heavily armed doesn't help. However, many of your pursuers do end up getting killed in cutscenes, sometimes even by the protagonist. As such, the purest example of this is the Stalker of Outlast II, which cannot be killed or fought in any way whatsoever; the fact that it's actually a representation of Blake's childhood trauma brought out by Murkoff's brain-warping radio signals doesn't help.
- Rayman 2: The Great Escape abruptly takes a turn for the horror genre during the mission to the Cave of Bad Dreams; the finale of this mission pits you against Jano, master of the cave, who cannot be fought — only fled from. For good measure, his massive jaws frame the screen as he closes in on Rayman, ready to slam shut...
- Resident Evil 3: Nemesis: The titular Nemesis who is a Recurring Boss throughout the game characterized by being an Implacable Man who is simply unkillable. While he can be fought, it only amounts to temporarily ceasing his pursuit. He will otherwise show up again, good as new, and keep coming for you over and over and over. He can only be killed permanently the eleventh time.
- The Secret World:
- Sachiko. The ghost of a girl who didn't survive the Fear Nothing Foundation's mind control experiments, she's currently haunting the Third Floor of the now-deserted FNF headquarters in search of anyone she can take out her frustrations on — leaving you squarely in her crosshairs when you're sent in to investigate. As her stats make clear, she cannot be beaten, forcing you to hide the moment you hear her approaching, then either run for your life while her back's turned or wait until she loses interest and leaves.
- The Bogeyman of The Park spinoff. The only real monster of the game, there's no way of resisting the Mind Rape he inflicts, no way of fighting him, and no indication that Lorraine could ever succeed in even vaguely harming him even if she could touch him. As it becomes apparent, The Park is actually a story of what happens when uninitiated Muggles blunder into The Secret World: they get screwed.
- Pyramid Head from Silent Hill 2 can be slowed down your attacks, but not killed. The first encounter simply ends after a fixed amount of time, after which he walks away (and will kill you if you follow after). This is played with in the penultimate boss fight, where the two Pyramid Heads have hit points you deplete like a conventional enemies, but while depleting them ends the fight, it doesn't kill them. Instead it triggers a cutscene where James realizes they are manifestations of his own guilt, after which they both kill themselves.
- Silent Hill: Shattered Memories has the Raw Shocks, the game's only proper enemy type which appears in the franchise's characteristic Otherworld, who can't be fought, turning every Otherworld sequence into a hectic chase with the monsters. This was presumably done in direct response to the criticisms of the combat-heavy Silent Hill: Homecoming.
- SCP Containment Breach has most of the hostile SCPs as this. The most prominent ones being:
- SCP-173, which Can't Move While Being Watched. Your only defense is to keep looking at it, to run away, or to close doors to delay its advance.
- SCP-096 who will kill you if you look at it. The only way to survive it is avoid eye contact with its face at all times. The second you look at it, you're dead.
- SCP-106, an Eldritch Abomination with phasing powers who loves to hunt its prey for amusement. You must always avoid letting him see you, otherwise he'll pursue you until he catches you. Unlike the other two examples, he can be deterred and recaptured but it's very difficult to do so.
- Slender: The Slender Man pursues you for the entire game. You can't fight it, hinder it, or even look at it (or else it'll kill you instantly). Your one defense is to run from it while collecting the 8 pages scattered through the woods, with each page collected making it more aggressive. The kicker is, even when you win and complete the objective of the game, "Slendy" still catches you and kills you.
- Slender: The Arrival: Aside from Slender Man, this game also adds "The Chaser", a proxy for Slender Man that is the main threat in Level 3. While lacking Slender Man's ability to teleport, the Chaser similarly can't be fought and only fled from, though unlike Slendy there is one defense against them which is focusing the flashlight on them which will cause them to temporarily halt their pursuit due to some discomfort from the light.
- None of the WAU-infected monsters in Soma can be fought; getting too close causes Simon to black out, forcing you to run or hide. It turns out this is because Simon is an Artificial Zombie, and the monsters are giving off so much electromagnetism that his mechanical components break down in close proximity. As it turns out, most of them were too strong to be stopped by the PATHOS-II personnel, who were usually forced to flee when confronted by them — or risk being violently incorporated into the WAU's Lotus-Eater Machine.
- In The Legend of Zelda: Spirit Tracks as you progress through the game, the tracks on the overworld feature Dark Trains and Armored Trains which can't be destroyed (the Dark Trains can be temporarily stunned by shooting them enough times, Armored Trains No-Sell your shots). They don't actively chase you (fortunately), but it's all too common to be trapped between two of them on a portion of track where you can't move out of the way, which is an instant Game Over. There's a grand total of one time in the game where they can be hunted down and killed, and that's just before the final boss.
- In Spooky's Jump Scare Mansion, the hostile specimens cannot be fought and all you can do is continue running from them from room to room, until you eventually lose them. If they catch you, they will attack you and eventually kill you.
- Super Mario Bros. 2 has Phanto, a flying living mask that pursues you whenever you grab a key and never stops hunting you... while you're holding the key. Dropping it causes it to leave, but it returns once you pick it up. There's a glitch that allows you to kill it, but it's very difficult to pull off. It's outright impossible to kill in Super Mario Maker 2 and, since you cannot drop the keys you collect in this game (this includes the Cursed Key Phanto is watching over), you cannot drive it away temporarily either, so your only salvation is to open a locked door with it.
- Gahan Wilson's The Ultimate Haunted House occasionally unleashes a monster on you, and unlike the other supernatural inhabitants of the House, they are automatically hostile towards you. As Gahan himself helpfully informs you, they cannot be placated, fought or defeated in any way. All you can do is leave the room as quickly as possible, or risk getting Cursed. For good measure, angering the House will result in monsters showing up more often.
- In Uncharted 2: Among Thieves, you cannot kill the pseudo-yeti that you encounter in the Ice Level. The point of the level is to run away from him, while shooting with a small pistol with a Bottomless Magazine, until you deal him enough damage to activate a scripted sequence where he leaves, synonym of your victory. However, if you play with the "Choose your Weapon" bonus option, you can use the "innocent" one-shot Tranquilizer pistol, and it will work better than anything.
- Throughout most of the Zork franchise, Grues are a very clear example of this: a breed of unseen monsters that dwell only in darkness, they will kill and eat anyone that isn't carrying a light with them. There's no way of fighting them, and the only way to avoid being eaten is to either leave as soon as possible or have a light of some kind ready. For added fun, they can be found absolutely anywhere of sufficient darkness: in Return to Zork, they can be found not only in dark forests and mine shafts, but in your hotel room.
- SCP Foundation:
- SCP-096, AKA The Shy Guy. It will kill anyone who looks at its face. However it doesn't matter how you look at its face, be it in person, via a security camera, or even a photo. It will somehow sense anyone who has seen its face and will hunt them down no matter where they are with nothing able to deter it until its accomplished its goal. Its also borderline Nigh-Invulnerable, with many attempts made to exterminate it that have ended in failure.
- SCP-173 is a Living Statue that Can't Move While Being Watched. It is in all respects, unkillable, and the only defense against it is to maintain eye contact with it at all times. In one story, 173 proves capable of reproducing, resulting in a disastrous breakout, massacre and a cataclysm that consumes all of North and South America. The Foundation is able to reduce their numbers via saturation nuclear bombing...and then a few more show up in Wales.
- SCP-4666, AKA The Yule Man. It can't be stopped, it can't be fought, and to date, none of the Foundation's teams have succeeded in catching up with it yet; for good measure, the Yule Man prefers attacking isolated rural locations in the dead of night, meaning that there's nobody around to help you. If you're a member of the family targeted, the only thing you can do is run... and that's only worked once.
- The Apathy from RWBY. While they are not particularly aggressive or physically threatening, they are perhaps one of the most terrifying types of Grimm seen in the franchise. These gaunt, slow-moving creatures as similar in behavior to a horde of zombies, and gather in large numbers wherever they establish themselves. Their namesake comes from their ability to generate a cloud of increasing apathy over an area, slowly draining victims' of their will until they simply lay down and die. Brunswick Farm became infested by a horde of the Apathy after an ill-advised attempt to use them to "take the edge off" the stressed settlers. Instead, the horde grew to massive size in the waterways beneath the settlement and the entire settlement eventually died in their sleep. Team RWBY eventually encounter the creatures after seeing numerous signs of their presence, and are nearly killed when their weapons prove ineffective. Even running proves futile, because the Horde's scream enhances their draining effect until even crawling away becomes too much work. The only method shown to work against the Apathy is the power of Ruby's Silver Eyes — this buys the group enough time to escape and burn the settlement down. The Apathy aren't slowed down by the flames, but at least the death trap of the settlement is destroyed.
- The Slender Man Mythos features one of these as the main character: the eponymous monster is not only unkillable, but his sheer power means that few of his victims ever get a chance to try attacking him. Most of the stories featuring him end with Slendy winning hands-down, and on the rare occasions in which he does have some kind of weakness, it can't actually do any real damage — it just dissuades him from pursuing his current target.
- In Ben 10: Alien Force, the episode "Paradox" features a transdimensional Eldritch Abomination that causes Rapid Aging in everything it touches. Ben's Team are completely helpless in fighting it and can only run from it. Turns out the creature itself can't be defeated directly, not even by Professor Paradox, and the only means of stopping it is to prevent its existence to begin with.
- A not-uncommon feature of nightmares, where the monsters often cannot be fought or defeated in any way — after all, it wouldn't be a nightmare if you actually won, would it?