Someone's put the hit out on you. But no matter, you're armed and dangerous yourself, and when the hitman catches up with you, [[AssassinOutclassin you get the drop on him, and simply put two in his chest]]. Problem solved, crisis averted.

And then he gets up, dusts himself off, mutters some kind of pithy one-liner, and [[RunOrDie comes after you again]].

You've just run into the Immortal Assassin.

This character shows up frequently in works of fantasy and science fiction. The professional killer who themselves cannot be killed. Either they are straight-out indestructible, or they possess a HealingFactor that lets them recover from any injury. Why they hire themselves out as hitmen can vary from character to character.

Depending on the universe, the Immortal Assassin may have been given their immortality through supernatural or technological means. Often, Immortal Assassins are [[ReallySevenHundredYearsOld much older than they appear]], not able to die of natural causes, and as such can have a bad case of [[WhoWantsToLiveForever "immortal angst"]] or [[LivingForeverIsAwesome "immortal smugness"]]. If they hail from a time and place before gunpowder was invented, they may prefer [[ElegantWeaponForAMoreCivilizedAge bladed weapons]] or hand-to-hand combat, eschewing guns as "uncivilized" or "clumsy." As a consequence, they will possess [[MasterSwordsman phenomenal martial arts skills]], honed from hundreds of years of practice.

Many Immortal Assassins consider themselves absolute professionals, devoted to the job at hand. They see killing as an art form, and make a serious effort to be as close to perfect as they can get. They may adhere to their own version of a "warrior's code," with a strong sense of personal honor. Often, this is because they come from [[ProudWarriorRaceGuy ancient cultures]] that put a great emphasis on honor and martial prowess, and they see their careers as an extension of that.

Of course, there are exceptions. Some Immortal Assassins are sadists who kill out of pleasure or out of boredom. Being unable to die has left them so [[WeAreAsMayFlies emotionally detached]] from the human race that killing mortals is little more than a game to them, a way to pass the time. Others are simply in it for the money. Some are just AxCrazy...

Most of the time, the ImmortalAssassin is the villain of the story. They can be a KnightOfCerebus, brought in by the BigBad when all other plans have failed, a genuine unstoppable badass more dangerous than any our heroes have yet faced. Maybe they're a DiabolusExNihilo. Alternatively, they may be a sympathetic character, particularly if whatever circumstances led to their becoming immortal or an assassin (or both) are tragic enough. On occasion, they will even do a HeelFaceTurn, join the heroes, and become TheAtoner. If part of an ensemble, they may even be used for comic relief; since ImmortalLifeIsCheap, the Immortal Assassin can suffer truly horrific injuries and shrug them off.

There may be ways in-universe to defeat the Immortal Assassin. The Assassin may have a carefully-guarded [[AchillesHeel weak spot]], or they may be injured so greviously that their healing factor simply may not be able to compensate. Another option is total physical destruction of the Assassin's body, so that there is nothing left for the healing factor to regenerate. Use of AppliedPhlebotinum may kill them, or [[BroughtDownToNormal deprive them of their immortality]]. Alternatively, the Assassin may be neutralized without being killed, imprisoned somehow, or even become SealedEvilInACan. Or in some cases, if the Assassin is just in it for the money and has [[PunchClockVillain no personal stake]] in the proceedings, simply calling off the hit will be enough.

There may be overlap with the ImplacableMan, particularly if the Immortal Assassin isn't entirely human.


[[folder: Anime And Manga ]]
* In ''Anime/{{Mnemosyne}}'', an assassin keeps trying to kill Rin, and keeps coming back, no matter how many times she herself gets shot, stabbed, and blown up. Fortunately, Rin herself is immortal too.
* Kakuzu of ''Manga/{{Naruto}}'' isn't quite immortal, but needs to be killed five times in one battle[[note]]or at least before he can restock by killing more people[[/note]] before he actually dies. He's also one of the oldest living characters; he was exiled from Taki for failing to kill the First Hokage, however many years ago that was.
** His partner Hidan, on the other hand, is pretty much defined by this trope. At the climax of the series he is still alive[[note]]since he could not be resurrected[[/note]], in pieces, and rotting.


[[folder:Comic Books]]
* {{Deadpool}}
* The Saint of Killers from ''ComicBook/{{Preacher}}''. [[spoiler:Not even God can kill him.]]
* The Kindly Ones from ''ComicBook/TheSandman'', although they can only be called upon to punish a kinslayer.
* {{Wolverine}}, before he changed occupations and became a full-time [[ComicBook/XMen X-Man]].
** And his OppositeSexClone, Comicbook/{{X 23}}, who was trained since birth to be this... until she too went rogue. Unlike her progenitor, however, Laura didn't ''choose'' to be an assassin; she was bred specifically for the task.
* The Talons from ''Comicbook/NightOfTheOwls'' probably qualify, since some of them are from at least the 1800s and their healing factor seems to protect them from most methods of killing them. The Court of Owls doesn't even kill them; they instead retire them, bringing them back eventually.

[[folder: Fan Fiction ]]
* The focus of the ''Manga/RanmaOneHalf'' story ''[[ Relentless]]'', though the killer is a [[OurDemonsAreDifferent demon]] (or even EldritchAbomination) known as the ''Reikoku'', sent to perform an assassination, rather than a normal assassin who happens to be immortal. Its weaknesses: it takes a day to come back to life, and if a single person can kill it three times, it will be banished back to its home dimension. Unfortunately, each time it comes back to life, it will have developed an impenetrable defense against any attacks used against it the previous time, plus it will have developed brand new attacks, including tailor-made FlawExploitation attacks. It might [[ItSeemedLikeAGoodIdeaAtTheTime seem like a good idea]] to destroy its corpse, but that just brings it back to life instantly. Oh, and if any of your friends attack it in order to help you, they get added to its hit list. And three ''total'' kills amongst you and all your friends aren't enough to finish it, it has to be three kills by the same person. Have fun!
* Inverted in ''FanFic/WhatAboutWitchQueen'' - while the assassin is absolutely mortal, his quarry proves much less so, to the surprise of them both.


[[folder: Film ]]
* Many characters in the ''Film/{{Highlander}}'' universe have made their living being Immortal Assassins, but most notably the Kurgan from the original film. He hires himself out to Clan Fraser in their battle against Clan Macleod, in exchange for the privilege of killing Connor Macleod himself.
* ''Franchise/{{Terminator}}'': Most terminators are specifically designed to be unkillable killers; the only way to make [[MadeOfIron the T-800]] in ''Film/Terminator2JudgmentDay'' seem vulnerable was to create an even deadlier terminator: [[BlobMonster the T-1000]].
* The character "Jaws" from James Bond's ''Film/TheSpyWhoLovedMe'' and ''Film/{{Moonraker}}'' appears to be immortal. He gets a pyramid dropped on him, bites a shark (not the other way around), drives off a cliff, slams into a cable car terminal, drives a boat over a water-fall and falls out of a plane. The mooks with him drop like flies, but he just dusts himself off and goes back to work. [[spoiler:The last we see of him, he's parachuting(?) back to Earth with his girlfriend.]]
* Karl Ruprecht Kroenen, the BigBad's [[TheDragon dragon]] in ''Film/{{Hellboy}}'', is a [[NinjaPirateZombieRobot quasi-undead Nazi ninja]] kept alive by clockwork cybernetics and sheer villainous willpower. His blood has long since turned to dust, making him ImmuneToBullets, and he keeps showing up again and again no matter what the heroes throw at him. By the end of the movie he's been taken out of the picture, but it's highly likely that, although trapped in an AndIMustScream situation the last time he's seen, he's still alive and available for a return in a sequel.


[[folder: Literature ]]
* The ''Gholam'' of Robert Jordan's ''Literature/TheWheelOfTime'' is basically an AntiMagic T-1000 designed as a literal MageKiller--so terrifying that only a handful were ever made. Only [[spoiler:AntiMagic artifacts like Mat's medallion]] (and probably starvation) can possibly do any damage, and that's not really a practical solution. [[spoiler:It ultimately ''does'' die some time after being forced into the VoidBetweenTheWorlds that is the Skimming dimension, however, but not without a lot of ingenuity.]]
* Ghost, of R.A. Salvatore's ''Literature/TheClericQuintet'' series, was a relative weakling who used a magic artifact to switch bodies, kill the target who is now in his weak body, and then heal it again using a magic ring of regeneration.
* James Spector, AKA "Demise," from the ''Literature/WildCards'' series. Originally killed by the Wild Card virus, he was resurrected with an experimental cure. He gained both a powerful healing factor and the ability to "project" his agonizing death onto anyone he made eye contact with, essentially killing them with a look. He was decapitated when a political assassination went wrong, and his body was destroyed by cremation when it became clear that he was trying to [[{{Squick}} GROW A NEW HEAD.]]
* The Night Angel from ''Literature/TheNightAngelTrilogy'' by Brent Weeks. He/she/it is literally immortal assassin although the immortality comes at a terrible price: [[spoiler: For every time he dies, a person of importance to him dies in his stead]]. Cue a whole lot of immortal angst and be done with it.
* The Mercenary from ''Literature/TheBartimaeusTrilogy'', while not ''strictly'' immortal, is incredibly resilient. Through his huge HealingFactor and [[AntiMagic resilience to magic]], he survived a long fall from a cliff, survived being smashed under a huge rock and survived magic that could ''destroy'' demons, let alone humans. Unlike most examples, he is not the main villain. [[spoiler: Although even he can die to a lot of very powerful, concentrated magic.]]
* Messers. Croup & Vandemar from Creator/NeilGaiman's ''Literature/{{Neverwhere}}'' are a pair of [[HumanoidAbomination Humanoid Abominations]] who stalk after Door, one of the main protagonists of the book, under orders of an unknown employer. They react to injuries with amusement or annoyance, they [[VillainTeleportation teleport seemingly at whim]], and may even possess limited time travel abilities, and they [[IAmAHumanitarian eat human flesh]]. Their true nature is never explained.
-->'''Mr. Croup:''' If we are injured, do we not bleed?
-->'''Mr. Vandemar:''' ...No.
* In ''Literature/LordOfTheRings'', when the Nazgul aren't Sauron's generals, they are his assassins. All nine were tasked with killing Frodo and retrieving the Ring from him, and it took intervention from the biggest heroes and healers of Middle-Earth to thwart the attempt.


[[folder: Live Action TV ]]
* ''Series/{{Lexx}}'' has an undead assassin, Kai, as one of its main characters. He is completely indestructible, and his long-term goal throughout the series is finding a way to die for good.
** Kai eventually faces an even more dangerous and indestructible assassin, the Divine Executioner Vlad.
* ''Series/{{Warehouse 13}}'' features Marcus Diamond, TheDragon to Season 3's BigBad. Technically he can't be killed because [[spoiler: he was already mortally wounded a long time ago, and he's using an artifact that rewound time for his body to just before his death. He's literally living on borrowed time.]]
* The ''Series/{{Highlander}}'' series featured several. [[MonsterClown Christoph]] [[EnemyMime Kuyler]] claimed to be the most prolific assassin in history, as well as the less theatrical Anthony Galen and Kamir, the last of the thuggee assassins.
* The Caretaker from ''Series/{{Alphas}}'' is virtually unkillable due to his high bone density, which he's able to regenerate so long as he has access to calcium. The downside of this is that this makes him very heavy, [[spoiler: which Kat uses against him to drown him]].
* River Song from ''Series/DoctorWho'' was abducted as a newborn and raised as a {{Tykebomb}} to assassinate the Doctor. [[spoiler: Having been conceived in the TARDIS, she possessed the ability to regenerate if killed, and had a lifespan measured in centuries.]]
* ''Series/DirkGentlysHolisticDetectiveAgency'': Bart Curlish, holistic assassin, essentially has official PlotArmor. Bullets swerve to avoid her, guns pointed at her at point blank jam, a knife hits her pommel first and bounces back... [[spoiler: But only if she's doing what the universe wants her to do, which usually is killing bad people. When she mistakenly tries to kill Dirk she gets stabbed, and when she refuses to kill Suzie Boreton she gets blasted with her new magic wand.]]

[[folder: Tabletop Games ]]
* ''TabletopGame/{{Deadlands}}'' give us Jasper Stone, an evil Harrowed who has progressed into a full-fledged Abomination, who works for the [[HorsemenOfTheApocalypse Reckoners]] themselves and [[HeroKiller shoots down]] dangerous heroes at their bequest. He was statless for a long time, for the explicit purpose of [[LordBritishPostulate not being killed by the party]].
* Liegenstrasse in ''TabletopGame/Warhammer40000'' is a result of splicing human and alien genome and the prime case of GoneHorriblyRight - with CastingAShadow, HealingFactor and full AnatomyArsenal, she proved nigh-impossible to take down and it was only managed by entire assassin temple. [[TheEndOrIsIt Maybe...]]


[[folder: Video Games ]]
* From the point of view of the enemies, ANY player character is one of these. Even if they manage to kill you, you just resurrect at the nearest save point and keep on coming. A few examples below are justified since their means of resurrection are actually addressed within the narrative of the game:
* Raziel from the ''VideoGame/LegacyOfKain'' series. Killed and resurrected twice already before the events of ''VideoGame/SoulReaver'', by the time the player meets him he is a soul-devouring revenant animated by an EldritchAbomination for the sole purpose of bringing down Kain and his empire. His physical body is essentially a half-rotted corpse, without skin, internal organs, or even a lower jaw. And if this body takes too much damage, he simply shifts to the spectral plane until he builds up enough life energy to return. And since time stops on the material plain when this happens, from anyone else's perspective he just pops out of existence and then immediately back in again at full strength. The Elder God specifically says he is "beyond death." He can't be killed because there is simply nothing left of him that's killable.
* Jack and Subject Delta from the ''VideoGame/BioShock'' series: functionally immortal because the game's equivalent of save points - the Vita-Chambers - are coded to their specific DNA. No one else in Rapture can use them, [[spoiler: except Jack's father, of course.]]
* The player character from ''VideoGame/TheElderScrollsVSkyrim'' can seem like this, having two methods (a perk and a mask) to automatically heal from near death.

[[folder: Web Original ]]
* The eponymous bad guy from ''WebVideo/TheHorriblySlowMurdererWithTheExtremelyInefficientWeapon''.