Himuro Genma from Ninja Scroll survives decapitation and more through his mastery of reincarnation. It takes being impaled by a roof timber and then covered in molten gold to finally stop him... for now at least. Theoretically, he may crawl out of the ocean some day as a homicidal gold-plated terror.
Blame! by Tsutomu Nihei has plenty. For one, there are Safeguard agents who can not be killed, only temporarily disabled/blown into pieces/vaporized, as they actually reside in virtual reality and can create remotely controlled bodies anywhere where a certain device is nearby. Oh, and they can instantaneously generate endless amounts of brainless robot Mooks who have razor sharp claws that cut metal like hot butter, are near impervious to conventional weaponry, and are really really fast and insanely strong. And then there's Killy, Artificial Human who walks through the whole world to find what he is looking for and is really really really durable. He was once buried under tons of molten metal and concrete and his near indestructible flesh was burned to his bone, but give him 14 years and he recovered completely, ready to continue his walk.
Petopeto-San has a character named Nuriko, who is a Nurikabe — Essentially, a wall monster. She is made of concrete. She only gets mad once, but the only way to stop her forward progress was to shove her off of the stage she was on at the time.
The Espada. One of them takes the hero's ultra-powerful, last-ditch attack which has defeated his previous opponents with ease... and gets off with a slight burn. He's not even the most powerful. Their leader, Captain Aizen, also does this: he effortlessly blocked the hero's best attack using one finger. The finger didn't even bleed.
Zaraki Kenpachi, who just grins after being impaled multiple times, and lets someone stab him just so he can get close enough to stab back.
Roberta, who in the space of two episodes hunts the protagonists through half of Roanapur, implacably getting through, in order, one shoot-out against twenty people all intent on killing her, the building said shoot-out was taking place in being detonated (by her, while she was inside, no less!), the ensuing inferno, a car chase that ends with her car flying from a rooftop and crashing into the side of a building, hanging onto the protagonists' car with a knife as they try to shake her off at top speed, being flung from said car into the side of a cargo container, a shootout with the Dark Action Girl heroine and finally a several-hour long fistfight. Which she stands up and walks away from after drawing with a Cross Counter. Oh yeah, and she's a maid by profession.
Lampshaded when the Lagoon Company directly compare her to the Terminator.
The El Baile de La Muerte manga arc/Roberta's Blood Trail OVA sees her go beyond even this, the whole arc being a one-woman killing spree against everyone standing in her way. In the OVA, is permanently crippled, losing a leg, an eye, two fingers on her right hand and the entire left arm to Grey Fox... And yet she keeps coming, though by the end it's ambigious who is the hunted and who is the hunter.
Sabrac from Shakugan no Shana. His physical humanoid form is only a small part of his actual body, so he's able to recover and regenerate from any attack.
Guts from Berserk, an understandably rare protagonist example, who will not stop until Griffith and The Godhands are dead, demon army after him be damned. Also, quite a number of the series' demons either are these or The Juggernaut.
Almost all of Hellsing's non-humans, including the mooks, and at least one empowered human count as Implacable Men. Hails of normal rounds barely faze them and they heal almost instantly.
One extreme case is Church Militant Father Alexander Anderson, who takes two headshots from explosive.454 bullets in rapid succession and gets back up almost immediately.
Another is Designated Hero and somewhatFriendly Neighborhood Vampire Alucard, who gets shot to pieces on three separate occasions only to rise, heal and mop the floor with his assailants. Admittedly, both of the above are anti-heroes instead of villains, but the bad guys do get their own Implacable Men, including aforementioned army of vampire mooks.
The Big Bad has on his side a Werewolf who's practically Made of Iron and a Catboy by the name of Schr÷dinger. He got his head shot off in England. He showed up in Brazil in the time it took the Big Bad to walk down the hall. Oh yeah, that "dead" thing? It got better. Oh yeah, and there's The good guy's former Battle Butler Walter, as a vampire
Lupin III is a franchise about the titular Gentleman Thief. The cop chasing him, Inspector Zenigata, is powered in his hunt by Justice. If he so much as lays an eye on Lupin, he'll start chasing the thief to the ends of the earth! Even killing him won't stop the Inspector. After being shot by the villain of Lupin III Island Of Assassins, he had been in coma for a while, and then his heart stopped. Upon seeing this, a fellow cop declared he would avenge Zenigata by capturing Lupin... And Zenigata promptly awakened from the coma, fully healed, trying to arrest Lupin, before returning to sleep.
Every homunculus from Fullmetal Alchemist, thanks in part to their Philosopher's Stone giving them unbelievable regneration powers. Some specific examples include:
Lust gets shot several times, exploded, and has her Philosopher's Stone forcibly yanked from her chest by Roy, and keeps on going. If Alphonse and Roy hadn't promptly cornered her and applied liberal amounts of flame, respectively, they'd all have been toast.
Sloth. Takes countless gunshots, numerous mortars, and a few exploding vehicles and keeps on truckin'. He barely even needs to use his regeneration; the military doesn't even kill him once. The only thing that manages to stop him is getting doused with gasoline and lured out into subzero weather. And that still doesn't kill him, just makes him stop for a while.
Then there's Greed!Ling unleashing his fury toward Amestris soldiers after Bradley killed Fuu, his trusted bodyguard. There's reason Greed got called "Ultimate Shield".
In the PokÚmon movie Lucario and the Mystery of Mew, the Regis fit this trope to a T. No matter how many Aura Spheres Lucario chucks at them, and no matter how many passageways are knocked down, they just keep walking slowly, inevitably, towards the heroes. Especially interesting is the fact that they manage to be implacable even while being constantly pegged by their mutual weakness to Fighting-types.
Vash and Knives from Trigun, seeing as, in addition to just not dying, even when pushed to the very limit of their powers, they never relent in their ideals either. A potent example is when Vash fires a clip of bullets at Knives. Knives turns the parts of his body where the bullets hit into guns and fires back. They both recover.
Has a variation that can only be described as...odd. Due to an unfortunate incident involving the Power Incontinence of The World Tree and a request for a kiss, Negi gets turned into an Implacable Man with the stated goal of french-kissing somebody, and the best efforts of several mages and fighters are powerless to stop him. He turned back to normal when he succeeds in kissing Asuna, nearly killing her by suffocation in the process.
Rikiya Gaoh and Jo Tetsuma from Eyeshield 21. Tetsuma runs with the speed of a freight train and hits about as hard, all while remaining perfectly emotionless and calm, while Gaoh's just a psycho who can't be stopped. Except by Donald Oberman, himself an example.
Goku, to the Red Ribbon army. He is relentless in wiping them out. Armies, mecha, older martial artists; he they might slow him down (one of them even forced him into a training arc) but he didn't stop.
Broly. His favorite hobby is chasing someone around in order to beat them up.
Majin Buu. He's been destroyed and vaporized, only to reform in the smoke and goes on to easily destroy Earth and nearly every character in the series.
Jin-Roh: The Wolf Brigade: Fuse has a touch of this towards the end. Clad in his standard issue bullet-proof armor, he ignores bullets and rifle grenades as he implacably advance through the Tokyo sewers, gunning down any who oppose him. Any member of the Kerberos Squad could be considered one while equipped with Protect Gear. The stuff is retro-Powered Armor.
Magellan, the prison warden of Impel Down. During Luffy's escape from prison, Magellan chases them the entire time, and it gets to the point that anybody that's caught by him is considered already dead as the prisoners run away from him, so what starts out as a riot of 5 floors and thousands of prisoners leads to less than 300 making it out alive. It's not that he's just unreasonably tough: his power is producing large amounts of poison, so that even touching him is suicide.
Though with that said, he did shrug off blows from EmporioIvankov, which appeared to have bruised him up a bit but otherwise fine. He also took multiple cannon-fire like a cake-walk.
Soon after Admiral Akainu gives Magellan a serious run for his money. Like Magellan, touching him is suicide (made of lava), like Magellan he gives chase to the protagonists and no one seems to be able to stop him, only buy a little time before being defeated, and unlike Magellan he's actually made good on his promise to not let anyone escape by actually killing Ace.
Due to being partially inspired by the Terminator, Bartholomew Kuma fits here, being an incredibly resilient cyborg and being able to redirect anything you throw at him. The short range teleportation and his primary method of movement being The Slow Walk just makes it worse.
Luffy's rubber body and Determinator nature gave him shades of this, particularly when upset. His fight against Arlong and moreso against Enel - whose powers were useless against Luffy - are good examples where he kept coming after them. Lately he's lost this status and went to full Determinator since everybody they fight has a power that can hurt him.
Smoker is like this to Luffy pre-Timeskip, back before Luffy could hurt Logia-types, and Smoker pursued Luffy relentlessly whenever their paths crossed and they weren't forced into an Enemy Mine scenario.
Almost every Awakened Being in Claymore. They do eventually die from Lowered Monster Difficulty, but boy do they take a lot of punishment. Some Claymores can as well. The Abyssal Ones are the worst of them, but they were eventually wiped out by even worse Implacable Women, namely the abyssal feeders, who were specifically designed to be relentless killers for the the Abyssal Ones by the Organization, and Priscilla, who is obviously even stronger and more Implacable than the Abyssal Ones.
Berserker had 12 lives and easily took any damage dished out to him. In the end it took some Phlebotinum to kill him. By easily took the damage we don't mean "he tanked that sword in the gut like a boss" we mean ""unless that sword was at least b-rank it didn't even BRUISE the skin" then of course the tanking comes in.
Souren Araya, a Buddhist monk who's been alive for 200 years. He has charms embedded in his body, allowing him to take blows that would otherwise kill him. Cut off his arm? He regenerates it without a problem. Cut off his other arm? It'll strangle you. Stab him? He won't even get wounded. Stab him in his point of death? No effect. Stab him in his point of death a second time after falling off a building? He's still alive for around 10 more minutes to converse with Touko before fading away to dust.His origin is stillness, after all.
Dennou Coil has the anti-virus program Satchii, a Killer Rabbit who relentlessly hunts down Illegal programs and illegal program users. Satchii and the little mechanical balls, Kyuu-chans, that come from him, are the general bane of the main characters of Dennou Coil. But once his limits are learned and Satchii becomes familiar, the even-more unstoppable version 2 hunters show up!
Shishio Makoto, one of the Big Bads of Rurouni Kenshin. He goes through the entire cast without stopping, takes a hit from the hero's strongest attack and stands back up, you name it. It takes his own body overheating to kill him. To be specific, he takes a direct punch from Sanosuke, hit very hard by Saito's in the forehead, and that's not even including Kenshin's attacks...
Randel Oland of Pumpkin Scissors becomes an implacable man when he uses his blue lantern. The twist is that he's just a large, strong, completely human Gentle Giant — he gets injured like anyone else would. Good thing most of his opponents are tanks crewed by rotten shots.
Yakumo from 3Î3 Eyes is immortal. The only way to kill him would be to kill Pai, and if you lay even a single finger on her, Yakumo gets unlimited power, meaning his healing ability becomes instantaneous and he can use his attack spells without restriction.
The Necrolyzed dead in Gungrave are invincible and always get back up even when riddled with bullets. Yes even the mooks. Their muscles continue to move even when it should be physically impossible.
Diclonius in Elfen Lied are practically immune to bullets (they won't even slow them down) thanks to a large number of invisible hands that block them. They are not invincible when fighting each other however.
Creed in Black Cat has some Phletbotinum juice that repairs his body from anything as long as there remains a single surviving cell of his DNA. To stop him takes a Phlebotinum bullet that can destroy every cell of his body, but because the one who fired it was a merciful sweeper who does not kill people it only hit him in the wings. More Phlebotinum, this time in the form of a syringe was used this time to destroy the nanomachines that made him implacable in the first place.
Kazuo Kiriyama in Battle Royale is this in all three versions. Despite being shot in the face, stabbed in the eye, hit with martial arts, he still gets back up, his expression just as dead, and shoots the offender. Egregiously shown during the fight with Shinji Mimura, who blew up a building with his homemade bomb trying to kill Kazuo... Only for Kazuo to calmly step out of a car that'd been hurled out of the building, and mercilessly gun him down.
Apocryphos from D.Gray-Man DEFINITELY counts as one. He or "It" is a sentient Innocence whose sole purpose is to protect the "Heart" of Innocence but upon his debut, his goal changes to assimilating Allen Walker although seeing as how he states he wants to do this to suppress the Fourteenth, this could also constitute as protecting the heart. How far is It willing to go to achieve Its goal? It infiltrated the Black Order as a yet unnamed Cardinal; "killed" Cross Marian who has so far been shown as the strongest and certainly most Bad Ass Exorcist; erased the memories of countless stooges; wiped Howard Link's memory and nearly killed him too if it hadn't been for a timely save; fought off two Noah simultaneously while trying to absorb Allen, damaging Road to the point that her "dream" was broken and she disappeared; has stalked Allen Walker for the past 3 months NONSTOP, through different cities and possibly countries; and most recently curb stomped Yu Kanda, erased his memories of the brief ordeal and may have killed Timcampy. And It's still going.
The Female Titan from Attack on Titan. Her relentless pursuit of Eren leaves a gruesome path of death and destruction in her wake, and is our first glimpse of just how terrifying humans with a Titan form truly are. She has the highest body count of any single Titan in the series, making her More Deadly Than The Male in so many ways.
A heroic example: Superman. Only if you hurt his friends and family, especially Lana, Lois, and Batman. Even then he won't kill you, or even try to make you suffer. But he'll definitely put you in a good solid inescapable prison cell for the rest of your life where you'll get to grow old and die on your own and won't hurt anyone ever again. At least until another author wants to use them More importantly, it's his primary crime-fighting style. He stands there and takes your best shot to show you that fighting him is pointless, then flies after you to show you that running is also pointless. Also, if you're attacking him, you're not attacking innocent people so it's worth the risk of taking the occasional punch that could hurt him. Unless you have a bit of kryptonite with you almost nothing can stop him.
The Hulk, especially if you pissed him off by hurting his loved ones.
In the first appearance of Judge Death in Judge Dredd, Dredd and a squad of Judges encounter Death committing a massacre. They open fire with standard ammunition to take him down, but the Dark Judge barely reacts to being hit multiple times while gloating "You cannot kill what does not live." However, the trope is then subverted by Dredd ordering him shot with incendiary ammunition which does bring down Death's body, even if the spirit escapes for the moment.
Jei-san from Usagi Yojimbo was supposed to be a creepy one-shot character who disappears after being struck by lightning. He mysteriously shows up again with the goal of killing Usagi and gets stabbed by his own spear and tossed off a cliff into a raging river. He gets better. He is Killed Off for Real when he gets stabbed by a mystical sword, but soon possesses the swordswoman Inazuma, then possesses another person after Inazuma's death... He gets better. After Usagi's first Single-Stroke Battle with him, they both freeze in shock - Usagi because he thought his blow was fatal, Jei because he thought he was invulnerable.
Spider-Man's enemy Morlun fits. "I hit him with everything I've got. He keeps coming. I hit him with everything I can find. He keeps coming. He doesn't talk. He doesn't snarl. Doesn't yell, gloat, preen, cackle, threaten or mock. He just keeps coming." A suitable runner-up for a trope-defining quote behind Mr. Reese if there ever was one.
In Special Forces, autistic manchild Zone is incredibly implacable. As the Desert Wolf, the enemy he was tasked to capture, finds with horror, "He is a demon! He has no fear!"
Walter from The Mask (comics and cartoons). Started out as an ordinary mook. Said one of his creators: "What doesn't kill him makes him Walter."
Played with in Too Much Coffee Man #4: The Death of Too Much Coffeeman. He has a heart attack, falls down stairs, falls out of a window, is shot, and has a safe land on him, among other things. He always has a clever explanation upon returning, sometimes in THE VERY NEXT panel (aliens, robot decoy, evil twin, and so on). Leads one of the supporting characters to lose interest and remark "Eh... he'll be back".
Marvel Comics has The Juggernaut, who is named aptly indeed. He literally cannot be stopped (one of his official superpowers is "once in motion, cannot be stopped" — he took a mystic blast from The Mighty Thor and it only staggered him for a few seconds), he's Nigh Invulnerable, and he officially has "infinite stamina". In other words, he never needs to stop. Ever. He doesn't eat, he doesn't sleep, he doesn't feel fatigue, he doesn't even breath. So once Juggernaut is on your trail, it doesn't matter what you do, he will find you, and there is nothing that will turn him back. Once the demon D'spayr tried sucking all the magic and life away from Juggernaut. He managed to reduce him to a skeleton, but Juggy still kept coming, fueled by pure anger and rage.
The Saint of Killers from Preacher. As a man he was a grim Bad AssBlood Knight of a soldier and then later a Bounty Hunter. The only bright spot in the blood soaked misery of his life was his wife, and later their child. So when a wretched band of lowlife outlaws prevented him from bringing them medicine when they were sick, he attempted to take revenge and wipe out the entire band, and only failed because he ran out of bullets. Upon arriving in Hell, his soul was filled with so much hatred that it froze Hell solid, and when the Devil attempted to whip and beat the hate out of him, the Devil had to give up. The only way to get him out of Hell was to let him take over for the Angel of Death, who was tired of the job. Now the Saint works as God's attack dog, armed with a pair of magic guns (melted down from the original Angel of Death's sword) that will never miss, never run out of bullets, and always be lethal, even if he's shooting at the Devil, warrior angels, or God Himself. Driving a truck into him will only result in the truck crumpling like paper. Tank shells will bounce off him without him noticing. Dropping a nuke directly on him will only cause him to spit in contempt and mutter "Not enough gun." He doesn't ever need to stop to rest, or eat, he will massacre innocents without remorse or compassion, and if he is ordered to hunt you, nothing can save you.
A hero example is Paul in With Strings Attached, who has been rendered immensely strong and Nigh Invulnerable. He tirelessly plows his way through miles of skeletons and zombies in his inexorable journey toward the ruined city on the Plains of Death. What finally stops him? A pair of wraiths (turns out he has no defense against intangible creatures) who suck out his abundant life energy (except he has so much that they both explode).
The Pony POV Series has the Wolf in Shining Armor's story. It is Nigh Invulnerable, and the most you can hope for is to temporarily slow it down or be near a divine being, whom it'll instinctively avoid. Just to highlight how powerful it is, Shining at one point shoots it point blank with a flare. It eats it.
The Fabrication Machine/B.R.A.I.N from 9. You defeat its little minion cat? Screw that, it can make a flying machine from a flag and skeletons to hunt you down. Defeat that too? It's already one step ahead of you with a creepy snake-thing that will catch you and bring you back to it, where it will certainly kill you. Light a barrel of oil and set a factory aflame and destroy the building in an explosion? All you've done is piss the thing off, and it'll drag its ruined body after you to steal your soul. Even getting caught in a bridge that it just destroyed on its killing spree won't slow it down because it'll find a way to climb out. Do you think shooting it in point-blank in the face from artillery only a foot away will stop it? Fuck no! It'll just bitchslap the weapon away and continuing coming after you. But a bit of green light shot into its eye? Yeah, that makes it explode from the inside out. Go figure.
The Sharptooth from the original The Land Before Time still goes after Littlefoot even after he is tail whipped several times into a mountain by a full grown Apatosaurus with enough force to shatter rock, falling several hundred feet into a chasm and being hit in the eye with a spiny vine. What finally does kill him is being lured into a lake then having a boulder dropped on his head.
Films — Live-Action
Perhaps the most potent distillation: the title character of the Terminator series is a killing machine, as discussed in the page quote.
The key example occurs near the end of The Terminator, where Kyle Reese manages to explode the fuel tanker truck that the Terminator is driving to try to destroy it. Immediately afterward, Kyle and Sarah Connor embrace with romantic music playing as they feel the crisis is over. However, the music abruptly changes back to ominous as the Terminator, now stripped to his endoskeleton frame, arises from the flames to shock both the heroes and the audience that the killer robot is still coming. Even after Kyle blows its legs off, the damn thing keeps crawling after Sarah with murderous intent, and as it's being crushed in a press, it claws at her with its metallic skeletal hand to the very last.
Taken to further extremes in Terminator 2: Judgment Day, where the T-1000 gets frozen by liquid nitrogen and breaks into a million pieces...and still survives to continue pursuing the heroesnote in the special edition, however, it sustained some damage to its shapeshifting ability due to getting frozen; he also manages to continue running at the same speed as a reversing car while being shot repeatedly with a pistol. Moreso with Sarah Connor's attack on Dyson's home, where she all but becomes a Terminator herself and is halfway to shooting a defenceless, wounded man dead in front of his wife and family.
The Tall Man from the Phantasm films. He can make you hallucinate that you killed him only to come back to torment you. He's telekinetic and super-strong, so it dosen't matter if you're close to him or not, he can still get you and cause your weapons to misfire or remove them from your grasp. Cut off parts of him and those parts will each become miniature monsters that will make your life hell. Freeze him and his head will release an unstoppable golden sentintel sphere. Finally you've somehow managed to burn him with fire, acid or blow him up, and his smoking corpse is on the ground, and you can take a breath....only to have an identical Tall Man step out of a dimensional doorway who picks up the corpse of the previous Tall Man and hurls it back through the portal, and then takes over immediately where the previous one left off. Did we also mention that he is a Reality Warper who can undo his own defeats, and has an ever-growing legion of the undead and alien technology at his command?
Gabriel Byrne's Satan character in End of Days (also starring Ahnold, this time as the human hero). He possesses the body of a stock broker, who proves impervious to bullets and other blunt trauma. He's eventually worn down by repeated explosive blasts and being mowed down by a subway train. When he can no longer walk, he simply leaves the broker's body and possesses a new one. In the end, Satan isn't beaten, only outlasted as the New Year rings in, and he's forced to retreat for another 1000 years.
Jaws from the James Bond franchise lives through two movies by sheer force of not stopping ever.
For that matter, Bond himself. Especially in the reboot he gets some truly epic chase scenes.
Probably the least potent film distillation: Ro-Man, the title character of B-MovieRobot Monster. All of our weapons have failed to kill it, and it's wiped out all of humanity, save about seven people. Under some circumstances, such feats would be really scary. However, since Ro-Man is a gorilla in a space helmet, this isn't one of those circumstances.
Agent Smith (and the other Agents) in The Matrix. Not only are Agents ridiculously powerful and ridiculously hard to kill, but if you do manage to kill one, all the Agent needs to do is find another human to possess in order to continue trying to take you down. There's a reason that standard Resistance procedure before Neo came along was to "run your ass off" when an Agent showed up.
Mal from Inception is a character that suddenly invades dream worlds and attempts to assassinate the dreamer. In a sense she's even worse than her counterpart Agent Smith in "The Matrix" movies in that she doesn't need to possess anyone, she just appears and wreaks havoc. What's really scary is that even in constructed dream worlds with trained dream operators, she's nearly impossible to stop.
Played for laughs with the random assassin in Austin Powers: The Spy Who Shagged Me: she survived a knife in the back, a dozen bullets shot in the back, a shot from a bazooka in the face, and a ridiculously high fall out of a window with Austin landing on top of her. A spot of Lampshade Hanging occurs when Austin cries "Why won't you die?!" A deleted scene shows that he keeps her in the trunk of his car to deflect gunfire.
The Beast from the film Kung Fu Hustle. Takes being punched through walls and flattened into the ground and still keeps going.
Realistically played by the main character from Brick. Takes a few beat-downs, but stands up again regardless (though his attempts to be truly implacable fail spectacularly when he swallows too much of his own blood and makes himself sick.)
The film The Punisher as well as the game, features The Russian who seems to be almost completely impervious to any kind of pain imaginable (in the game he is even immune to bullets even though he doesn't have any super powers). He is based on the Russian character from the original comics, who is a lot more talkative, but just as supremely strong and relentless; he was only defeated when the Punisher suffocated him under his obese neighbour and then cut off his head, but he still came back after having his head reattached and his skeleton augmented with powerful metal alloys (he also received a pair of breasts due to hormone injections, which he took in stride by actually dressing up like a woman on occasions).
Another bulletproof Russian (Uzbekistani) appears in the movie Snatch, and hilarity ensues.
Even when not dodging bullets, he manages to survive being hit directly by a car travelling at high speed with no real injury, then taking almost a full clip from a desert eagle at the hands of Bullet-Tooth Tony, all while yelling "fuck you!" with each bullet that Tony puts in him. It's heavily implied by his tenacity that he would have survived if the frustrated Tony hadn't used his last bullet for a well-aimed headshot.
Drug usage seems able to confer apparent-Implacability. A lesser kind of Implacable Man appears in Scarface: Tony Montana snorts cocaine and then takes on an army of assailants. Despite being shot numerous times with automatic weapons, he doesn't flinch and kills every one of his would-be assassins. Only a double-barrel shotgun blast delivered from behind at point-blank range is enough to finally take Tony down.
Jason Voorhees from the Friday the 13th movies is nearly impossible to stop, and it's always temporary.
Jason X adds a more heroic Implacable Man to the mix with Sgt. Brodski, who seems to repeatedly survive all sorts of damage on sheer force of will alone.
In Freddy vs. Jason, Jason proves how implacable he is during a fight in dream world - despite being near-omnipotent in dream world, Freddy finds himself unable to kill Jason, before discovering his hydrophobia.
Imhotep from The Mummy. Immortal, the only way to actually stop him is to magic him back to mortality and then kill him.
Marv from Sin City. He's so tough he taunted his own executioners after they gave him his first round on the electric chair. He defeated the psychopathic Kevin by handcuffing them together and taking everything Kevin could dish out until he could get one good punch in. Throughout the film, he takes an almost superhuman amount of punishment without flinching.
Kazuo Kiriyama in Battle Royale. Even after brutal hand-to-hand combat with a highly skilled martial artists, a leap out of a speeding car, a spearhead to the eye, and several gunshot wounds, including one to the face, he's still on his feet and dangerous.
Anton Chigurh from No Country for Old Men definitely counts, although the film handles it more realistically than most. The next-to-final scene proves Anton is definitely killable - he's just single-minded, completely unfettered by any conventional morality, and very good at his job. Then again his car crash at the end shows that he is not completely invincible, and that pure luck might also play a part in keeping him alive.
The Golden Army of Hellboy II. Even after getting torn apart, they rebuild themselves.
Godzilla, King Kong, and other similar giant animal monsters. Guns? Tanks? Fighter jets? Nuclear weapons? Shrug. You need a seriously plot-specific item to take out one of these guys. Well, Kong was killed pretty easily, by beauty.
The Repo Men in Repo! The Genetic Opera are hired on the basis of their having this trait, though usually it's displayed in more... subtle ways before they get the job (for example, Nathan's relentless search for Marni's cure.)
Dorian Gray, as portrayed in the movie version of The League of Extraordinary Gentlemen probably also counts. In an early scene in the movie, he's seen getting riddled with bullets, which only succeeds in destroying his suit and making him mildly annoyed.
Subverted in V for Vendetta: title character V takes a massive barrage of bullets with a comparatively very minimal reaction, has a teensy bit o' trouble breathing just afterward (after all the bad guys are completely out of bullets)...... and then proceeds to completely annihilate everyone and everything, until he gets the Big Bad alone, hoists him up in the air and snaps his neck with one twitch. The subversion part comes when he opens his cloak to reveal the medieval breastplate that only "sort of" protected him. Cue long-winded Heroic Sacrifice.
The elite marshall squad in Butch Cassidy and the Sundance Kid. Butch eventually comments, "Don't they ever get tired? Don't they ever get hungry?...I wish they'd even speed up, at least it'd be different."
For a non-superpowered or supernatural slasher the titular villain from The Stepfather films commonly survives things no normal man possibly could - in the first movie alone he gets shot several times and knifed in the chest, getting only a small scar from the encounter. It takes being chewed up and liquefied in a woodchipper in the third film to finally kill him.
Halloween series: Michael Myers in the seventh film, after getting an axe in the chest, nonchalantly rips the weapon out and keeps going. Though apparently you can convince him to go away by dressing up like him, but once the costume comes off, you're just another target.
The Neo-Vipers from G.I. Joe: The Rise of Cobra are first shown walking calmly through massed assault rifle fire with all the rounds bouncing harmlessly off. While they are later shown to be susceptible to explosives or a Moe Greene Special, it does make them look intimidating.
The Adventures Of Captain Marvel feature the title character as a heroic version of one of these. Often times the criminals will fire bullet after bullet at the Nigh Invulnerable hero, while the Captain calmly walks forward with a 'you are SO going to get your asses kicked' smile on his face as the bullets shatter against his body.
Colonel Reza in Duck, You Sucker!. Over the course of the film he is repeatedly blown up, only to get up and come after Juan and Mallory again and again. It takes having a machinegun emptied into him to put him down for good.
Sebastian Shaw in X-Men: First Class, most notably in the scene where he invades a CIA base to try to recruit the mutants being housed there. Getting repeatedly hit by volleys of machine gun fire doesn't even muss up his suit. He No Sells an energy blast that's later shown slicing through the walls of a nuclear fallout shelter like butter. The only thing they can hit him with that even slows him down is a bazooka, and then only because it takes him a couple of seconds to absorb the blast.
The killer in Midnight Movie gets shot several times. Justified in that he's just a character from a film brought to life.
Star Trek Into Darkness has John Harrison take half a dozen of Kirk's best haymakers to the face without so much as a bruise. In the end, a mildly-annoyed Harrison resorts to snark. Harrison also shrugs off crashlanding a starship into parts of San Francisco and is still conscious after being stunned about six times in succession with a phaser. He even successfully weathers out a Vulcan nerve pinch!
In the Syfy Channel Original film Scarecrow has the title entity. It literally can't be killed period. Shooting it, burning it, even being shredded into tiny bits do nothing but slow it down. It will always regenerate and keep coming. The only way it can be defeated is to imprison it somehow. And even if you can do that, the moment it gets loose, it'll resume it's hunt as if nothing happened.
Vain, the magically constructed being in the Second Chronicles Of Thomas Covenant, is an Implacable Man but not a villain. Instead, he spends most of the time doing very little and being vaguely ominous while he follows the heroes around and shrugs off all attacks.
The Cauldron-Born in the Chronicles of Prydain; they are invulnerable, and all strategies for dealing with them revolve around drawing them away from Annuvin (because they grow weaker when outside it) or delaying them. At the ennd it is revealed that they can be killed by Dyrnwyn, the black sword. In The Movie, The Black Cauldron, that Implacable Army can only be defeated by someone jumping into the titular cauldron — to their death.
Shrike from Mortal Engines, last of the Lazarus Brigade, survives being shot and stabbed (a lot), being blown up, being run over by a mobile city, and ten thousand years of entropy.
Bartimaeus: "Whether I squished him under a statue, blew him up with a Detonation or (as in our last encounter) simply set him on fire and hurled him down a mountainside, he never seemed to suffer the slightest injury."
Having one of these sent after him (in the form of Mr. Pump, a golem) is what convinces Moist von Lipwig to give in and serve as postmaster. Golems do have a weakness, though: they can handle fire, and they can handle water, but being living clay, they can't handle both at the same time.
Another, earlier golem example comes in Feet of Clay, in which Angua remarks that, despite its cracks, the golem king would probably keep attacking even if it became nothing more than floating dust.
The Luggage. Even if you go to the ends of the earth, the Luggage will be heading there with its hundreds of tiny feet. It's also rather vicious. Ends of the Earth? It will follow you to the beginning of time or its end, into another dimension, or through the gates of Hell itself, utterly destroying whoever and whatever gets in its way.
And a human example: Sam Vimes. "As far as they're concerned, I am far-reaching consequences!" Yes, he is.
Older Than Steam: In book V of Edmund Spenser's 1596 poem, The Faerie Queene, Talus, the iron sidekick with a penchant for incredibly violent justice, proves unstoppable by any of his enemies.
Many Dean Koontz antagonists fit this trope to a T. If they want the heroes they will hunt them, and hunt them, and hunt them until they are killed or incapacitated. Often very competent and capable of tracking their quarry through their connections. But thankfully the same can be said of the protagonists, whose spirit to live and Divine Intervention save the day.
In Glen Cook's Black Company books, all magic users tend to be hard to kill, but the worst by far is the Limper. For starters he gets stabbed a few hundred times, hacked apart, mutilated, knocked out of the sky, then decapitated. It doesn't stop him. Eventually he is shredded to tiny pieces and boiled in a giant pressure cooker, and the gooey mass of flesh and gorestill breaks out and tries to keep going.
In Glen Cook's Petty Pewter Gods, one of the Garrett series, "Nog is Inescapable."
Vago, the golem from Storm Thief. Not only is the guy next to impossible to harm with conventional weaponry, Revenants, which instantly kill everything else by brushing up against them die the instant they touch him, and give him energy. Granted, he was designed to kill them, so that bit is justified.
Croup and Vandemar in Neverwhere, who cannot be killed and doggedly pursue the heroes until the end.
The Bible, in the Book of Job, mentions a "leviathan" and "behemoth" that apparently shrug off all human attempts to subdue them, at least if the quite literal Word of God is to be trusted.
The gods of the Everworld series are, not surprisingly, rather hard to kill. You know, being gods and all. However, what is required to actually kill them varies according to book. At first, they can be killed only by another god or the weapon of a god. Period. Later on, it is said that Hel could've been vanquished by an enchanted sword, and one character says that a fall into a crater the group is at would kill even an immortal. Nonetheless, gods are stabbed with swords, cut with blades, and shot full of arrows with little effect over the course of the books. It is possible that the books' Coo-Hatch steel could kill an immortal, however.
The Warrior Bugs from Starship Troopers, at least according to Johnnie. It takes losing all four limbs on one side to topple one, and it's not out of commission till the nerve case is damaged. If it hasn't been toppled by then, it can still charge forward until it bumps into something like a wall.
The Steel Inquisitors of Mistborn: The Original Trilogy can only be killed by decapitation or pulling out the metal spike embedded in their back- they'll recover almost instantly from anything else. Their boss, the Lord Ruler, is even tougher- prior to the beginning of the book he had reportedly been stabbed, shot, decapitated, burned and flayed alive and shrugged it all off like nothing. Word of God says the decapitation was an exaggeration, he was only partially decapitated and would have died if he'd actually been completely decapitated.
Hyde from The Strange Case of Dr. Jekyll and Mr. Hyde is a chilling deconstruction of this. Although we don't see him shrug off lots of damage, the point is made clearly - if absolutely, positively nothing is going to stop you, then surely that must include even the innocent little girl who just got in your way. Which is indeed what happens when Hyde callously walks onto her. In the face of this monstrous behaviour the observers are disgusted.
Several characters from The Dresden Files, but most notably Cowl, whom a fallen angel-powered Harry flipped a car onto and it did nothing. Wizards are the GlassCannons of the Dresdenverse. Also Nicodemus. He gets shot full of a full clip of bullets without even flincing. After the second bullet he actually started making the quintessential "can we hurry it up" gesture.
The Vampire Lord Haputmann Constanza from the novel series/2000 A.D. comic Fiends of the Eastern Front can reconstitute himself from the smallest grain of ash. Getting shot with silver-plated anti-armor shells doesn't stop him, and getting decapitated by a propeller only slows him down.
The Princess Bride has a Badass Normal example. Sure, the Man in Black is technically just an ordinary human without any superpowers or invulnerability, but... When following Buttercup's kidnappers, he outraces the fastest ship in the land, climbs the original Cliffs Of Insanity, even after they cut the rope, beats Inigo Montoya in a duel, wrestles Fezzik unconscious, and finally deliberately drinks poison without suffering any effects to beat Vizzini in cunning.
All of The Undead armies in The Malazan Book of the Fallen (the T'lan Imass, Forkrul Assail, and K'Chain Che'Malle) have this as their hat. From what we've seen of the Jaghut Tyrants they also count, as do Annomander Rake and many of the series other Bad Ass characters.
The Golem of Flesh, Everyman from the Way of the Tiger gamebook series. Everytime you killed him, he would reappear, repeating his line "I am Everyman.". After the first few fights, even if you took no damage(through fudging the dice, or just being really good at rolling them), you'd still lose hitpoints on each subsequent attempts, as "exhaustion" kicked in. The only way to get away from him: Lure him to a cliff and make him fall. Incidentally, said cliff leads to hordes of monsters who will gladly keep him occupied for eternity.
The Irrha from Tad Williams' The War of the Flowers, a mindless disease spirit that someone sends to kidnap the main character. It follows him everywhere, even between dimensions, constructing a new body from whatever's handy (trash, stray cats, parts of a homeless guy, whatever). In the end, it can't be stopped from carrying out its mission- but it can be sidetracked onto the Enfante Terrible for whom the changeling protagonist was switched at birth.
The Percy Jackson and the Olympians book The Last Olympian has Hyperion, Big Bad Kronos' Dragon, plus Kronos himself. Percy Jackson, once he takes a dip in the River Styx is almost a deconstruction as he is an Implacable Man when he needs to be, but once the need has gone, he feels all the more tired for it.
Nearly any greater dead or free magic construct in the Old Kingdom trilogy unless you have exactly the skills and equipment needed to handle them, and any of the dead are this when faced with modern weaponry.
Michael is a heroic version of this in the Knight and Rogue Series. Due to suffering from Chronic Hero Syndrome he eagerly pursues the villains, and when they finally confront him and throw him over a 300 ft high cliff he just gets winded.
In Simon R. Green's Verse, the Walking Man is an agent of holy wrath who cannot be stopped by any force short of divinity. Anyone who becomes one will believe God is backing his play, and he'll be right.
The Lifeless in Warbreaker are an implacable army. They're essentially zombies that are perfectly obedient to whoever has the authority to command them. As such, they're completely fearless, completely tireless, don't need to eat, and can shrug off any injury as long as it doesn't directly impair their fuctioning. Furthermore, though they lose their free will they do retain learned skills, so where other undead would just Zerg Rush, Lifeless who were soldiers in life are fully capable of using advanced combat techniques and tactics. Taken Up to Eleven with Kalad's Phantom's, legendary ultra-Lifeless created as Elite Mooks by a Sorcerous Overlord and ultimately revealed to be composed of skeletons sealed inside solid stone, making them all but impossible to destroy. Good thing for the heroes that their creator did a Heel-Face Turn and is now The Atoner...
In the Fighting Fantasy book Knights Of Doom your character inevitably encounters the assassin's dagger, an invincible, disembodied hand clutching a dagger whose only purpose is to kill the you. You can run away, you can fend it off, you can even trap it inside a heavy box, but the assassin's dagger will keep catching up with you at multiple points throughout the adventure. If you don't find a way to banish it before the end of the book then it will sneak up on you and bury itself in your back just as you confront the Big Bad.
Arenad from Fallen Moon, at least in book three. After suffering multiple mortal injuries, he is eventually killed by drinking a bottle of the deadliest poison in universe. He gets better in a few days. For some examples; he was turned into a human pincushion, fell off a mountain, starved to death, likely broke his neck a few times, and stabbed through the heart twice, one of which was with a magic BFS designed by a god to kill him.
In a collection of Pacific coast Indian folktales there was one in which a group of hunters find that the "old woman" who took shelter from the winter in their lodge is actually a brain-eating monster. They hit it on the head with a hatchet, then burn the lodge with it's body inside. Then lead it on a chase across the country-side setting traps for it as they go until they finally lure it onto thin ice and it falls through, and was presumably released again come spring. Since there were no other versions of the story from other tribes it was probably made up on the spot by a storyteller who would have been writing for Hollywood except it was the 19th century.
By the time of Todd and Viola's final confrontation with him, Aaron has pulled through being mauled by a crocodile, almost drowning, getting his nose torn off, and more through the power of his own twisted faith. Horrifying disfigurement is a small price to pay for the fulfillment of his mission. He only dies for good when Viola puts a knife through his neck and he goes over a waterfall.
The Kull Warriors of Anubis and The Replicators from Stargate SG-1. Anubis himself is a border-line example: he has the survive-anything-you-can-throw-at-him part, but since he is a Galactic Conqueror he doesn't just show up trying to gut the heroes but sends armies after them instead. Sadly, they have this trait.
Adam, up until the spell the Slayettes use on Buffy... then Buffy turns into this.
Willow from during her evil magic moments.
Buffy did a lot of these. Subverted with the Judge. All the mystical texts declare that "no weapon forged" can stop him. However, as Xander realizes, those texts predate many modern weapons. Therefore Buffy takes out the Judge with a rocket launcher.
The Beast from season 4 couldn't walk very fast due to huge posture and massive, cloven feet. It pursued its intended targets without haste but relentlessly. Bullets bounced off of it, swords and axes broke on its skin, even a pair of hand grenades blowing up in his face failed to slow it down. Angel did try to drive a stake through its one possible weak spot, being the eye, but quickly found his strength was no match for the Beast's, who promptly caught the stake and stopped him using it.
Marcus Hamilton (aka Jayne Cob, aka John Casey) at least until he revealed his weakness to Angel.
Many of Doctor Who's aliens chose to invade Earth during the late 20th century, and inevitably the army would find that bullets/bombs/missiles/tanks barely scratched the surface.
In the 26th-season serial Battlefield, the Brigadier shows the Doctor gold bullets for dealing with Cybermen, Teflon non-stick bullets that "go right through a Dalek" and muses that, just once, it would be nice to encounter an alien menace that wasn't Immune to Bullets.
The Doctor himself would seem to be a good candidate for this title. He may not be physically invulnerable, but Regeneration combined with his legendary stubbornness means that he Will. Not. Stop. The basic arithmetic of Doctor Who is this: Five million Cybermen < Four Daleks < One Doctor.
The Huntsman of The 10th Kingdom. Not only does he get caught in one of his own traps, in a world where presumably medicine is at a medieval level and magic may not be able to combat infections, he gets hit over the head (twice!), once by an extremely heavy iron torch swung with incredible force which should have smashed his skull or at least given him a concussion. And yet he still keeps waking up and coming after the heroes. His analysis? "I move slowly...but I always get what I want. Nothing escapes...the Huntsman." It finally takes a Hoist by His Own Petard moment to bring him to his Karmic Death.
The Borg, from Star Trek: The Next Generation. You defeat one or two of them, and the rest are able to adapt to whatever you used against the first ones. We did see a submachine gun kill two Borg drones, however they probably would've adapted their shields afterwards to deflect bullets too. Their ships are far more impressive, being far beyond the combat capabilities of the series' protagonists. Ontop of that, putting up any kind of defense that harms them will make them interested enough to dissect and assimilate everything about their "victim". They will then pursue this goal with a Terminator-like doggedness.
Q: They will follow this ship until you exhaust your fuel. They will wear down your defenses. Then you will be theirs.
Q: You can't outrun them. You can't destroy them. If you damage them, the essence of what they are, remains. They regenerate and keep coming. Eventually you will weaken. Your reserves will be gone. They are relentless!
Star Trek: The Original Series The Gorn from the episode "Arena" is pretty implacable for most of the episode, even shrugging off a small avalanche caused by Kirk. Kirk is unable to harm the Gorn or stop its attempts to kill him (sluggish as they are) until he improvises a primitive cannon.
The T-888 Terminator called "Cromartie": In the first episode he was shot multiple times, run over by a car, had a live wire shoved into his neck, is blown up as the same car that ran him over exploded and ripped in half by a terminator-destroying gun. He reactivates himself eight years later, dresses up like a post-apocalypse survivor (complete with gas mask), gets its head back, steals medical supplies, gets a scientist to help him regrow his skin, then takes the guise of an FBI agent, working to find Sarah Connor from the inside. The first season finale has him take out a SWAT team raiding his apartment(!), but spares the life of an FBI agent who is also tracking the Connor family.
In a Season 2 episode, a Terminator is sent back to kill the governor of California during a specific time. He is accidentally sent back to the 1920s and kills the architect who designed the building that the speech was held in. The terminator proceeds to start his own architecture firm, go to great lengths to acquire the land, and construct the building himself just so he can pull off the termination as he was ordered to do.
Also, in the second season opening, Cameron goes berserk and becomes an Implacable Woman as she pursues Connors, trying to kill them.
Divine Assassin Kai from Lexx. Chop him to bits, and he'll reassemble himself — but he'll probably finish killing you first. Energy Weapons are completely useless, even when they're mighty enough to destroy whole planets. On one occasion, he singlehandedly fought his way through 50,000 heavily armed soldiers, killing 2,807 of them, in order to assassinate a single man whom they were guarding.
One episode of Hustle had an implacable bounty hunter (or "tracer") named Pinky Byrne.
Played for Laughs on Red Dwarf. Rimmer suggests that tax collectors are like this, and that even being three million light years from Earth in a universe where the number of surviving humans is in single figures doesn't guarantee safety from them. Rimmer himself becomes one of these after being upgraded to Hard Light. This is well balanced though, because his light bee is still vulnerable in extreme situations (like potentially being sucked out into space), and he is also a complete coward.
Theokoles from Spartacus: Blood and Sand. Besides his tremendous size and strength, he takes incredible damage without stopping. He allows Crixus to impale him so he can grab his wrist and trap him. His neck is so thick that he can't be decapitated in one strike.
Duncan Macleod on Highlander tended to get this way when pursuing Immortals who had murdered innocents.
"Run, little boy. I will find you."
In the episode Halloween Reese and Dewey accidently egg an old man who took too long to show up to the door. He spends the rest of the episode chasing them down with his walker, until he catches them in a trap. He then proceeds to throw eggs at them while they can't escape.
When Kane first debuted, he was implacable. He no-sold everything, and his first two matches were one-sided squashes against Mankind and Vader. It took The Undertaker three tombstone piledrivers to beat him, and he had to do a leg hook pinfall instead of his usual pose pinfall.
Many "monster" heels probably count; no-selling and squashing their way to victory, up until the point a top-level face eventually defeats them.
The Undertaker himself is one such implacable man, regardless of his alignment, and defeating him is treated as Defeating the Undefeatable. He best exemplifies this trait during WrestleMania and WrestleMania'' season, when his streak is on the line. Ending said streak is said to be the holy grail, an accomplishment greater than winning a world championship, and a one-way ticket to the Hall of Fame.
Abyss gets cast in this role quite often. For a long time TNA put him in matches where he would take bumps on thumbtacks, barbed wire, broken glass, etc. and he would just keep coming.
In Captain Scarlet and the Mysterons, this is the basic super-power possessed by any Mysteron clone. Emphasized a little more in the original series, where their implacability was due to being Nigh Invulnerable, but even the remake version count, as they're implacable in the sense that if you kill them, they come right back to life and come after you again. Fortunately, the main character is a free-willed Mysteron clone, so he too never stops, no matter what is done to him.
Warhammer 40,000 has a race of Implacable Men: the robotic Necrons, who can stand back up after anything — which in the Warhammer 40,000 universe starts at being riddled with lasers capable of blowing limbs off, crushed by artillery rounds the size of houses and having your head bitten off by daemonically possessed super-soldiers. They even have a special rule for it: We'll Be Back. Space Marines and Daemons are effectively of this sort to "normals" too.
Comissar Yarrik is a Badass Normal example of this. He lost his arm fighting against an Ork warboss, but still managed to kill him, tear off his power claw and hold it triuphantly in front of the Ork army, causing them to flee in panic. Only then did he pass out. Later he also got his eye shot out and replaced with a bionic implant and had his command tank explode. He's dedicated his life to hunting down the Ork warlord Ghazkull Thraka and seems to have no intention of stopping despite being an old man by now. He even has a special rule similar to the Necrons "We'll Be Back", where on 3+ he simply refuses to die and stands back up with one wound. It's hinted that the Orks have seen him crush their armies so many times that they've started to view him as unkillable, and since Orks run on Clap Your Hands If You Believe, their belief is making him unkillable. Notably, Games Workshop always gives his models a slight greenish tinge in their official painting.
Second edition 40k had different rules for armor saves, with base armor and save modifiers. This means that the Terminator armor, at present only failing a save on a 1 on a d6 (except for armor-ignoring guns and melÚe weapons), used to roll two dice and fail only on snake-eyes. Even if hit by the biggest weapons in the game, they would be unscathed on rolling 9+ on two dice. Abaddon the Despoiler ramped this up into Unwinnable by Design territory by the fact that he saved on a 2 on 2d6. Unless you had a meaty gun that imposed modifiers on the save roll, you would always save.
Space Marines in the WH40k universe are examples of this trope. Not only do they have redundant organs, they can go into a (controlled) coma to repair damage. Their blood clots instantly, and their armour dispenses painkillers and stimulant drugs as a backup. One example had a Marine keep fighting after getting his arm blown off and his molten armour fused to his side by an energy fire. This example is relatively mundane compared to some of the stuff a Space Marine can push through.
The Primarchs are examples of this trope. It took other Primarchs, daemon weapons or overwhelming force to kill them. One broke a greater daemon's spine over his knee.
A mysterious force aided humanity in the 13th Black Crusade which is rumoured to be the fabled "13th Legion" of the Space Wolves. If this is true, then they have been fighting in the Eye of Terror for over 10,000 years against all 9 Traitor Legions and all the Daemons of the Warp and are still a strong and effective fighting force. Doesn't hurt that further rumours have them being led by Leman Russ, which would make him the only currently active Primarch as all the others are dead, have become Greater Daemons or have otherwise been indisposed for the last 10,000 years. Though 10,000 years passed in the materium (real space). Time in the warp flows differently, which is one of the reasons many members of the original Traitor Legions are still alive.
Leman Russ himself showed strong traits of this when he first met the Emperor. The two fought, the Emperor in his battle armour and Leman Russ with no armour or weapons and was not only able to fight the Emperor for hours, but also knocked him clear across the room with a single punch.
GURPS has an Advantage called "Supernatural Durability" which makes you immune to all shock, stun, & knockout. As long as you have positive health you are immune to crippling injuries and have full move. With negative HP you have half move and can be crippled. You can only be killed in two ways: by an attack which does 10 * your maximum HP, or by using an item you're weak against and reducing you below -5* HP. For comparison A normal human has half move and dodge below 1/3 of their health. Below 0 HP they must make a roll each turn or fall unconscious, and must make rolls to not die at -1* HP, -2* HP, -3* HP, -4* HP. At -5* HP you die immediately, no save.
The Dungeons & Dragons game has this built right in—sort of. In earlier editions, characters simply had hit points and died only when they reached 0. Characters could be hurt, but they generally weren't bothered by it unless an effect also had a condition attached to it. Later editions made it slightly more believable, as once you reached 0 or lower, you simply dropped unconscious, and if you were at below 0, you bled out until you reached -10, at which point death ensued, but included abilities that allowed a person to be a true implacable man, able to take full actions while at negative points, until they reached -10 and keeled over.
One particular class, the Frenzied Berserker, takes it a step further. They are capable of completely ignoring negative hit points, even below -10, while they are frenzying. They can easily hit double- or triple-digit negatives, and if a skilled (or lucky) healer manages to get enough spells off to return them to positive hit points before the end of the frenzy, they come out none the worse for wear. The only effects that can kill them in this state are the ones that don't deal hit point damage, like suffocation or instant-death spells. The cost for this ability is that they are required to continually attack, and if they run out of enemies they start chewing through allies... Although if you want him to be near unkillable, you need a necklace that makes it so magic that instantly kills you doesn't work, a stone that makes it so you don't need to breathe, and finally to double up on a magic ring that makes it so - should something kill you and you'd get a save against it - you can choose to delay it for one minute, nine times for one ring. Hopefully you don't accrue enough damage that your cleric can't heal you within 180 rounds.
Add on a Ring of Regeneration, and you'd have someone unkillable except by having the hand with the ring chopped off and incinerated or dissolved in acid after the above is done. (This Ring prevents death from anything except spells that directly cause death as long as it stays on your finger. While fire and acid damage cannot be regenerated, as long as you're still alive they will heal back at the base rate of 1 hp per day. Obviously, if you no longer have fingers, you can't keep wearing it...)
The Tarrasque: regeneration 40, magic-reflecting carapace, 840 hit points (this in a game where even the luckiest—as in, win the lottery several times—non-epic tank will have no more than 600, and then only for short bursts at a time), and immunities to everything under the sun. Not only that, but to kill it, you have to reduce it anywhere from negative 10 to negative 40 (depending on edition) hitpoints and subsequently cast wish or miracle—generally the most powerful non-epic spells in the game—to make him stay that way...for awhile.
To top that, the Tarrasque can flat out not be killed in 4th edition DnD. Instead he can only be driven back to the center of the earth to slumber.
From the Elder Evils sourcebook is Zargon The Returner, an Eldritch Abomination that sucks up damage almost as well as the Tarrasque. Unlike the Tarrasque, though, even if you actually kill him he'll just grow back around his indestructible horn within a few days. The only way to keep him down for good is to destroy his horn, and good luck with that.
Inevitables are Terminator expies—extraplanar constructs that enforce universal law, combining the relentless single-mindedness of a machine with the intelligence to plan ahead and strategize. On top of that, destroying one will only make the forges back on it's home plane reassemble it, and send it back in with the exact same mission, only with the added knowledge the last one managed to provide. Fortunately, they usually don't seek to kill, only to enforce whatever law was broken, and will punish it accordingly, usually by forcing compliance through magic or handing the culprit over to local authorities. Of course, if it's the kind that punishes grave dodgers, you're probably out of luck: If it's your life that's extended, it'll beat you to death right then and there.
The recently-released "Heroes of Shadow" supplement added in vampire as a class. You start with only two Healing Surges (normal characters range from 6 for a particularly Squishy Wizard to 15+ for The Big Guy), but when you bloody or kill a foe, you can suck their blood to gain an extra healing surge. If you end a fight with more healing surges than your base, the excess burn off and you're instantly at full health. Oh, also, you do not fall unconscious when at negative hit points, but you DO have to make death-saving-throws, and you CAN still die if reduced to negative half your health (which is instant death for anyone else.) That said, a fair GM will rightly have the last remaining enemies of a fight soiling themselves in terror as everything else on the battlefield is dead or dying, yet this one mutilated, bloody thing that has been tearing their comrades apart with bare claws and teeth is still coming at them.
In 7th Sea, there is the "Man of Will" advantage, rendering one immune to any mind-altering magic, immune to fear, immune to the effects of the Repartee system (ie, no one can Charm, Taunt or Intimidate you), and immune to the effects of being Crippled. Likewise, while you can't get a Hubris with it, it does give you a discount if you wish to purchase a Virtue. Needless to say, for a point based system, it is a very expensive advantage if a starting character wants it.
In Deadlands: Reloaded and Deadlands: The Classic Collection, there is actually no known way to stop the Reckoners (though a later game, a side story to Hell On Earth, allowed you to fight them) and most of their servitors can only be killed in one, very specific way (eg: Jasper Stone, servitor of Death).
The "Slasher" supplement brings us the Mask. Built for murder and only murder, these mindless killing machines can take a pistol clip to put down (if you're lucky), and never need to sleep or eat.
Prometheans. If these guys want something, they just WON'T. STOP. EVER. Sure, you can wound them and they will feel the pain. But they won't get knocked out. They will just keep walking towards you. If you take them down(say, with an artillery bombardment)? They WILL JUST COME BACK TO LIFE 24 hours later. Don't mess with the Created if you know what's good for you.
To a simultaneously lesser and greater degree, the Bound can soak a full health track of damage by spending plasm and, like Prometheans, aren't knocked out by anything short of a full track of the worst damage that can be dealt (though unlike Prometheans, they do still start to bleed out at the same point mortals do). They've got more natural resurrections than the Created do (albeit at a price).
Role Master had the Dark Reaver, a black, indestructible suit of armour possessed by a demon. Usually set up as a guardian of a treasure, it would pursue thieves by simply walking after them, grabbing the stolen items and walking back with them. Any attempts at stopping them tended to be futile, since it was also carrying an indestructible axe (and knew how to use it). "You guys can have the rest - I call dibs on the black armour"
Has Zsofiska the Kite Flute, a demon that can be summoned to hunt down someone you want dead. Her movement speed? Always one foot per round faster than her target. Regardless of the target's movement speed. Also there is nowhere you can go that she can't follow. And demons are killing machines, even when fighting isn't their primary thing, so good luck fighting her off. And if you, upon summoning her, don't give her a target, she'll find someone to kill. Probably anyone who's standing close to you at any time. (So if you're an Omnicidal Maniac you may as well summon the demon and just walk around without giving her a specified target.)
With the correct Charms, Green Sun Princes don't need to sleep, can eat virtually anything (or subsist on murder), and can outrun virtually anything, while being able to take megadamage hits clean on the chin without slowing down. Abyssals can channel the relentless inevitability of death. Lunars can be the ultimate Super-Persistent Predator. Solars can follow you anywhere, overcome any concealment and open any lock. Dragon-Bloods aren't quite as powerful, but when they hunt you down they bring friends. Even Sidereals can get in on the fun with things like One Direction Invocation.
Generally speaking, in any system that allows them to achieve sufficient levels of toughness and badassery, suitably motivated player characters can easily become just this.
Joshua Graham, the former right-hand man of Caesar in Fallout: New Vegas. Time and again he'd be beset by numerous NCR Elite Mooks and reported dead, only to reappear days later, completely unharmed. When he failed to win the Battle of Hoover Dam for the Legion, Caesar set him on fire and threw him in the Grand Canyon to ensure he'd stay dead. And he managed to survive that and trekked his ass all the way back to Utah. In Honest Hearts, he has a Damage Threshold of 50 which is greater than anything the Courier could end up with without very specific speccing and DLC perks.
The PC "The Courier" also qaulifies as at the start of the game they are shot in the head by a 9mm at close range. After spending a few days in the local clinic they get back up march out into the mohave and slaughter everything in their path. With the DLC's included, they also have their brain, heart and spine removed and are actually better off for it (they have synthetic replacements installed for their Heart and spine and tesla coils funtioning as the brain), left in a poinsed city filled with other unkillable monsters (see below), and simply walk away with all the guns and gold they can carry
The Ghost People of Dead Money after years of exposure to the cloud are nigh on immortal, silently stalking you through the city, unable to talk through the heavy clothing they wear, dragging travverlas of to beneath the city to do... god only knows what to them. Worse is that you don't have ANY good guns to begin with, just your holorifle and 18 bulk Microfusion Cells. After being left alone for 30 seconds a 'killed' Ghost person will simply start up again like a wind up terminator.. Disintergration, Decapitition, Dismemberment and Dog (who eats them) are the only ways to ensure that they won't get back up again and start chasing you some more. Oh and in order to get into the Seirra Madre you have to start up the Gala event. Which attracts the attetnion of almost every Ghost Person who was hiding beneath the city till then. So you then have to fight you way into the Seirra Madre, through the cloud, past some 30 Ghost People. Have fun.
Fallout 2 had Frank Horrigan a 12 foot super mutant in Power Armor who laughs at the ideal that plasma fire can kill him.
In Super Mario RPG, however, jumps are considered magical attacks, which Dry Bones are very weak to. As such, they can be felled quite easily with a single jump, whereas physical attacks such as Mario's punches, hammers and shells cannot kill them.
In Paper Mario, Jr. Troopa takes everything you can dish out and comes back for more time and time again. If you use Goombario's tattle ability, he'll keep getting more impressed with Troopa's tenacity each time.
Pyramid Head: Usually the only way to survive an encounter with him is to run your damn fool ass off, and hope he doesn't catch you. The game suggests the Pyramid Head is merely a gatekeeper whose purpose is to herd you in the right direction. He is never truly defeated; he merely strolls away menacingly or kills himself once his purpose is fulfilled. In that sense, he is closer to a Juggernaut.
Walter Sullivan from Silent Hill 4, at least until the boss battle when his defenses are finally lowered. The Ghost Victims of the game also apply, since they will keep chasing Henry from level to level unless pinned down by a (very rare) sword.
Lisa Trevor. Eventually she commits suicide by throwing herself off the platform you're on, after you expose her mother's corpse. And she somehow shows up again, none the worse for wear, to attack Wesker several times in Umbrella Chronicles.
Tyrants (games 0, 1, 2 and Code: Veronica) also count. You will always have to fight a Tyrant at least twice, and with the exception of the Proto-Tyrant in Resident Evil 0, killing one always requires the use of high explosive. Guns, grenades and immersion in molten metal will not be enough to kill one. Given that Tyrants are meant to be Super Soldiers, this is to be expected.
The Tyrant T-103, the beta version of the Nemesis encountered in Scenario B of Resident Evil 2, deserves special mention. He wants Sherry's locket, which contains a sample of the G Virus, and absolutely nothing will stop him from getting it. Towards the end Leon/Claire drops him into a smelting pit, and it only pisses him off.
The Nemesis from Resident Evil 3: Nemesis. He's the only enemy in the game that can follow you from room to room and outrun you. It takes at least 14 shotgun shells to kill him on EASY MODE. No, wait, it gets better. You don't "kill" it with fourteen shells on easy. You knock it out. Nemmy'll show up later. Throughout the course of the game, he gets repeatedly shot, blasted out of a train with a grenade, passes out into burning helicopter wreckage, soaked with acid, and by the end, he's been decapitated, falls into a pit of acid designed to break down BOWs, and still doesn't stop. Well, that's okay, it's a scripted enemy, right? Wrong. Unlike the vast majority of such creatures, while the Nemesis does have some scripted battles, it can attack you at random. There is nowhere you are safe from it.
Resident Evil 4 actually gives a kind of subversion with the Regenerators. From the first meeting it seems that nothing can stop them... Unless you're really lucky with blind firing or high-end explosives, as we later find out that they simply have hidden weak points that can be revealed later. Bad guys like Mendez and Saddler, however, still play the trope straight, with Saddler ejecting the bullets from his body through his hands. And then there's El Verdugo. Luckily, it is possible to finish the game without killing this guy, which is probably what most players do, their first few times around.
The Verdugo is so hard to kill, that some players are left with the impression that he's a Hopeless Boss Fight and that he simply can't be killed, only escaped. He's more vulnerable under the effects of liquid nitrogen but it still takes a ton of firepower to take him down.
Albert Wesker himself. He survived being slashed/impaled by Tyrant due to his regenerative Psycho Serum, and having a load of girders dropped on him, and can dodge bullets and catch rockets Matrix style. Until he mutates into a One-Winged Angel form at the end of RE 5. Even then he can survive the heat of lava, and takes a barrage of rockets to the heart before dying for good.
He plunged his hand into the container, laughing maniacally as the Uroboros swarmed up his arm.
Resident Evil 6 gives us Ustanak, the monster whose only goals are to brutally murder Jake and Sherry and try to outdo Nemesis for the coveted title of "Most Unstoppable Killing Machine". Even getting a DRILLING MACHINE THROUGH THE CHEST only defeats him for about one chapter.
It also gives us the Rasklapanje , an expy of the Regenerator above. Except this time there's no magic technique; you just can't kill them. Period. Thankfully, they only appear in one short segment towards the end of Leon's campaign.
Big Daddy in Rapture and The Songbird in Columbia. The former, a sort of clockwork Papa Wolf, is a loose example as he won't attack you unless you provoke him. You might assume from his dense armor that Big Daddy can't keep up a hot pursuit. You would be mistaken. There are several models thoughout the game, and two variations (one with a drill, and another with a rivet gun.)
The Songbird, a giant robotic sparrow who patrols the tower Elizabeth is imprisoned in. It's only goal is to return Elizabeth to her gilded cage, meaning it's possible to appease Songbird by simply handing her over. It takes the entire game to finally turn Songbird to scap metal.
And then there is the Motorized Patriot, who in his introductory video is actually described as being this, He feels no pain, he does not falter, no sense of self-preservation, he has no Cranial Processing Unit, so really, you can shoot at him until he's dead but he will not stop.
The Black Knight/General Zelgius from Fire Emblem definitely qualifies. He's invincible to all but the main character's BFS (which you get in the last few chapters of the game...), at least in the first game. A whole castle falls on him, and he comes back just fine in the sequel.
Haunting Ground: The game's main claim to fame is that the player is chased by this type of individual once a chapter. These beings have different approaches to chasing the heroine, such as their attention span or diligence in finding her hiding spots. The best one can do before their boss fight is to run away, or knock them out via dog-mauling or alchemic munitions.
Debilitas (The Caretaker) serves as an introduction to the game's premise. He's not as durable or persistent as later stalkers can be, and can be knocked out somewhat more easily. That being said, he shouldn't be underestimated.
Daniella (The Maid) is made of this trope; she is incredibly difficult to knock out, and when that's achieved, she gets up quite quickly. She will relentlessly stalk Fiona, pretend to not know where her hiding spots are and will purposely lock Hewie in rooms and attack him to draw Fiona out if she genuinely has no idea where she is. This is even lampshaded during her Boss Fight if she's knocked out:
Fiona (in journal): Even that didn't stop her?! What is she, the maid from hell?!
The invincible Tall Man. Depending on his mood, he'll just walk towards you, or teleport Dragon Ball Z style and butcher you effortlessly.
Death (the security guard boss) from House of the Dead 3 shows up not just once but TWICE! One of the characters comments on its one tracked mind and persistancy.
The SA-X in Metroid: Fusion. Somewhat more complicated in that it's a copy of the heroine, with all the Metroid-killing equipment she wielded at the end of the last adventure. The real heroine starts off pitifully unpowered by comparison, and is now part Metroid to boot. Talk about stacking the odds against you. At first you can't do anything against it and just have to run away, but later on you can freeze it to slow it down.
Samus herself is also an example. This is especially clear in the Prime series where you can read Space Pirate logs that speak of "The Hunter" as an unstoppable killer capable of obliterating their entire armies singlehandedly.
The Metroids themselves, unless you're packing a cold based weapon.
Dark Samus, a near unkillable doppelganger of Samus who thrives on Phazon and can come back From a Single Cell. Best displayed after beating her near the end of Metroid Prime 2, where she uses the last strength she has left to crawl towards Samus and attempt to grab her for one last attack before collapsing, eerily similar to another Implacable Man. Then she returns in Metroid Prime 3, and is more dangerousthan ever.
After it is released in the third section of the PC game Vivisector: Beast Inside, the Overbrute Panther becomes an Implacable Man; while you can blast whole chunks out of it, it won't be slowed one iota by it, and will instantly regenerate, and unless you find some way of locking it out temporarily, it will always catch up with you and kill you with a casually-placed detonator to the chest. Oh, and it can turn invisible at will, as well, to both sight and radar, making it even harder to avoid the monster. Games designers are sadists, clearly.
The first game with an Implacable Man. Berzerk had Evil Otto, who shows up if you are slow in clearing the room of robots. Not only was he invulnerable, but could pass through the electrified walls that would kill anything else that touched them, including the robots that were also trying to kill the player. Otto would also destroy any robots that were in his way, and in some rooms the only way to get the bonus points for killing all the robots was to lead Otto through a walled off chamber in which the last robot was hiding. Otto would gradually speed up over time, and instantly go to maximum speed (twice as fast as the player) once all robots in a room were destroyed, making death at his hands unavoidable unles the player was very close to an exit.
In the sequel to Berzerk, Frenzy, Otto could actually be killed by four laser shots (either from players or robots). Every time he died, however, he would return from the same spot he spawned one second later, moving slightly faster than before. Killing him was worth quite a few points, but his movement pattern (bouncing vertically like a ball viewed from the side, even though the game actually used a top down perspective) made scoring hits very difficult unless directly above or below him, and this was the most dangerous place to be while fighting him due to the horizontal screen and the bouncing movement making Otto able to cover vertical distances much more quickly. It didn't help that missing Otto with a laser blast could result in the player's death from his own beam, due to new laser-reflecting walls present in the sequel. Finally, Frenzy included some special rooms, including the nightmare inducing "Mama Otto" room, dominated by a giant (but thankfully motionless) Evil Otto. Until you set it off...
Fatal Frame II had the Kusabi, a guy who was unphotographable at least until the penultimate boss fight.
Dead Space has The Hunter, aka the Regenerator Necromorph, an artificial Necromorph created by the ship's resident Mad Scientist that steadily pursues you through the ship over several chapters. Notable for not only enduring all damage the player can inflict and brush off the effects of being cryogenically frozen, but after luring it into the path of a ship's thrusters and testing them, it can still be seen trying to crawl towards you as it melts to death.
Dead Space 2 does this again through The ▄bermorph in the final chapters; whilst it is still relentless and able to regenerate limbs in moments, it is presented as an Elite Mook by sudden unexplained appearance (and by it functioning primarily as an invincible mook rather than a plot device like the aforementioned Hunter).
Dead Space 3 ups the ante by throwing several Regenerators at Isaac in one level. He remarks that he REALLY hates those things. They're put down for good when the docking bay vents and they wind up spaced (this doesn't kill Necromorphs, but a Necromorph floating in perfect vacuum isn't in a position to kill anyone).
Alma from F.E.A.R.. You actually do face her head-on at the end of the game... but even then, you don't so much defeat her, or hurt her, as vaguely annoy her into leaving you alone.
Jake and Francis Fratelli in The Goonies (NES). The sequel introduces a third brother, but he can at least be defeated.
The G-man from Half-Life is a variant: You don't have to fight him, but he does follow Gordon Freeman all over the place, finding routes through places that Gordon must fight through and getting to spots before Gordon can.
However, if you do feel like popping off a few rounds at him before he disappears round whatever corner, they simply bounce off with the bullets-on-metal sparks effect and sound (at least in the original; in HL2, like all important or allied NPCs, he simply cannot be hit by weapons).
Gordon Freeman himself. By Half-Life 2 he is feared as a One-Man Army by the Combine, and worshipped as a hero by the humans in equal amounts.
In the Devil May Cry series, enemies on DanteMust Die and higher difficulties have a Devil Trigger power that they can use, making them nearly immune to flinching and much harder to kill. Vergil in the third title represents the Implacable Man ideal more accurately. When he uses his Devil Trigger (on any difficulty, BTW), he doesn't flinch from attacks, takes them without being scratched at all and regenerates health. While he can be knocked out of it, showing the state to be merely a brief flirtation, it is hard enough to do so. When he assumes the Super/Desperation Devil Trigger in the final fight, he can't be knocked out of it, but he does halt after some time, though not before regenerating at a higher rate than in his normal Devil Trigger.
This is justified in that when you DT, you get the stun resistance yourself also, as well as the regenerative factor.
Enemies? Dante gets impaled with his own sword in every installment. This somehow fazed him only the first time it happened. Must have been the novelty.
An enemy/creature from Pikmin, the Waterwraith, is invincible unless you have purple Pikmin at your disposal. Unfortunately for you, you don't have any purple Pikmin when you enter the cave he dwells, and won't get access until you've reached the final floor.
Liquid Snake from Metal Gear Solid survives a helicopter crash, an arseload of missiles that only succeed in blowing up his Humongous Mecha, a forty foot fall from the top of said Humongous Mecha after being punched off it during a fistfight, and then a barrage of gunfire to the face followed by a jeep crash. He is finally killed by a tailored supervirus-induced heart attack. And then he comes back in the sequel as a talking arm. But not really.
Vamp from Metal Gear Solid 2 and 4. Survives being shot in the head and heart, filled with lead and dumped in a vat of no-resistance fluid, shot in the head again, stabbed multiple times (with he himself pulling a blade stuck in his chest out through his back), and shot a few more times before the Applied Phlebotinum keeping him alive is finally deactivated.
Ocelot (before he gained the nickname "Revolver") in Metal Gear Solid 3. While not entirely murderous, he seems obsessed with besting Snake after tasting humilating defeat early in the story. However, he is hogtied by his own sense of honor, which forbids anyone else helping him (or Snake dying at anyone else's hands but his own).
Raiden becomes this in Metal Gear Rising: Revengeance. Once he learns that World Marshall is planning to create an army of child soldiers using the same training regimen that was used on Raiden, he decides to take them down. And no one, not Maverick, not enemy cyborgs, not the Winds of Destruction, hell; not even Sam could stop him in their rematch. Oh, and Raiden can now slice open his foes and steal their nanotech to heal himself completely, making him even more difficult to stop.
Kratos from God of War. And when he does die, he just slaughters his way back to the land of the living.
The Reaper from Persona 3, also known as "Death." It exhibits the "slow walk" by showing up whenever you take too long to advance to the next area. Even your support character warns you that you "can't defeat it!!", and tells you to get out immediately. It can be defeated it very high levels, but even if you do, it will still come back for more.
Speaking of Scarface, In the pseudo-sequel The World Is Yours, Tony can enter a Blind Rage, where he exhibits true Implacability. He becomes immune to attacks, doesn't flinch, gains auto-aiming and the quasi-vampiric ability to heal by attacking enemies. Although it lasts for only brief periods, it can be reused and the meter needed to fuel it can be filled up fairly quickly. For that matter, Tony in general; he's gonna take Miami back and kill Sosa, and heaven help the chazzers stupid enough to get in his way.
Also in The World Is Yours, Big Bad Alejandro Sosa exhibits apparent-Implacability the way Tony did at the end of the film, taking whole clips to the chest without flinching. Even from the mighty Desert Eagle that instant-kills everyone else. A good few headshots are needed to end him.
In addition to what has been mentioned about Warhammer 40,000, the Dark Crusade expansion to Dawn of War gives Eldar Fire Dragons the effective mass of super-heavy tanks without compromising their agility. Although they do not have the durability of most other examples on this page, the not-too-shabby health they possess results in a bunch of base-wreckers that can sprint through air strikes, artillery, orbital bombardment and God-Emperor knows what else without being tossed around like most other infantry. Yes, that list of infantry includes Da Ork Warboss. They form a point of contention regarding Eldar imbalance.
Solus from Breakdown is indestructible to the point where all you can do is run, dodging laser traps only to see him just walking through them - these laser traps would kill you the second you touch them, and yet he just walks straight through them without even a burn mark to show for it.
In Command & Conquer, Kane has survived being shot at by a giant space laser, and also being run through by a piece of debris. He comes back for yet another sequel.
Then again some do legitimately end up with so much HP they can outright ignore frightening levels of damage. Imagine what the human Mooks think of the human looking protagonists of most RPGs. Samus or Link with all of their health upgrades are another example. Beam of radioactive plasma?
This is lampshaded in Pratchett's novel Only You Can Save Mankind where the Screewee Empire are genuinely fearful of the protagonist's ability to keep coming back every time they kill him, since they're a videogame antagonist race who are somehow real. When he points out it must surely be the same for them being as he's played one level many times and there's always three ships, they simply answer "different ships."
Also lampshaded in the Metal Slug series. When one of your One-Hit-Point Wonder characters comes back from the dead — either through using an extra life or using a continue — all enemy soldiers on-screen briefly freak out over their inexplicable resurrection.
The Lobstermen of X-COM: Terror from the Deep, like their predecessors the Chrysalids, will give this impression when you first encounter one. You fill it with harpoons, your squad opens fire with Gauss pistols, you launch torpedoes at it... and you watch in horror as it somehow survives it all and proceeds to mow down your troops.
Humorously done by Allen O'Neille in Metal Slug. In the second game he gets eaten by a killer whale upon defeat and still comes back for the sequels. When asked about his immortality, the game staff responded that the reason he never dies is because he both "has a body of steel and guts", and he has a wife and son to return to at the end of the day (a strange inversion of Fatal Family Photo there).
Max Payne can get plugged with hundreds of bullets in the course of the game, but doesn't seems any worse off, as long as he has a supply of painkillers to dull the pain. Lampshaded by the Big Bad of Max Payne and again by the Big Bad of Max Payne 2:
Nicole Horne: (Max Payne) What do you mean he's unstoppable? You are superior to him in every way that counts. You are better trained, better equipped, you outnumber him at least 20 to 1. Do... your... job!
In the second game he survives being shot in the face. He doesn't become mentally retarded or dysfunctional from it either.
The Cyberdemon in Doom can mow through masses of lesser mooks with its rocket launcher and One Hit Kills the player unless your health and armor are at nearly 200%. It takes roughly 400 bullets to be put down, which is twice as many as you can carry without a backpack, and it's resistant to missiles, which are unfortunately the only kind of ammo that you'll find in its lair. It's so tough that a strategy guide simply put "shoot at it until it dies" as a tip, as some players back then seemed to think it was unkillable. The fact that you don't have the BFG at that point doesn't help. Not to mention it had better stats (health, speed, pain chance) than the final boss, who shows up one whole episode later.
In Disaster: Day of Crisis, Ray is practically this - he survives several natural disasters while fighting an elite former special forces unit, and he just still keeps coming after them on his own out of sheer willpower to save Lisa. Major Evans also has this trait, taking an ungodly amount of bullets to the face (and calls their first fight a draw after he takes so many bullets!), mans a Metal Gear expy while still taking even more bullets (or rockets) to the face, and can give Ray a hand-to-hand battle before Colonel Haynes finally shoots him square in the forehead. That guy must have a really special gun.
RuneScape had a couple of these guys that you saw that is implacable in general:
First one is Lucien in While Guthix Rests, an evil Mahjarrat, during a cutscene where a series of heroes go and try to fight the guy. .. well, needless to say most of them bit the dust for good and they DO NOT come back.
Second Nomination will be the Corporeal beast, a result of Nice Job Breaking It, Hero. It comes to the corporeal realm to deliver a can of whoop ass for anyone willing to take a one way trip back to Lumbridge. Before it came to the corporeal realm, it was MERELY trapped in theSpirit Realm, siphoning energy off the souls of a dead family for two quests. And then you show up. Naturally, living soul energy is much more potent than dead soul energy...
The final nomination will be Vampyres and Vyrewatch, monsters that can't be beaten with even a Godsword, instead until you have a silver weapon, good luck fighting these guys.
Tsukihime has a few of these as well. From Arcueid being cut into 17 pieces and coming back to life the next day, Roa being taken down to nothing but his ankles and immediately regenerating, and Nero having his body ripped in two only to make fun of the person who did it. They have this trope covered.
The Ballistikraft robots from Rise of the Triad. Invincible, hulking robots that roll towards you very slowly, shrugging off anything and everything you fire at it and spewing rockets at you. The only thing you can do is run.
Definitely fitting the description on later difficulties is the Tank from Left 4 Dead, surviving clips upon clips of high-powered rifle and shotgun rounds and surviving complete immolation for upwards of a minute. Combined with how hard he swings, his implacability entered my nightmares.
The amount of his HP varies from 4500 to over 6000, depending on difficulty, with a wee bit over five goddamn thousand in the Versus mode. When in doubt, Kill It with Fire.
Common infected could occasionally become absolutely immortal thanks to a bug. Using a cheat engine that displays infected health doesn't even give comforting high numbers (like 999,999), it reveals that they simply do not exist as far as the computer is concerned. AIs will simply give up and let the Implacable Zombie kill them, and the only way to survive is to shove it into a room, close the door, and rush through the rest of the level.
Due to a bug in damage collision, it's entirely possible to hit a zombie with a melee weapon (almost always a one-hit kill on anything not a Charger, Witch or Tank) and see it's head get taken clean off, only to have the game register it as a miss. The zombie in question is perfectly killable if you can land a second swing, but until then it will come at you bleeding and without a head.
The Phantoms from The Legend of Zelda: Phantom Hourglass, which cannot even be stunned until you get the bow about halfway through the game, and cannot be defeated until you get the necessary legendary sword shortly before the end of the game.
A benign example from the same series: the Postman, particularly in The Legend of Zelda: Twilight Princess. It doesn't matter where you go, what you do, or what lies between you — he will bring you your mail! Even if you pull off the glitch of making him fall into the abyss of Hyrule Field, he'll STILL bring you your mail.
Then there's the Bublin King, who you have to fight four times. And in two of the fights he falls into a cliff upon defeat.
Another Zelda example from Twilight Princess is the two Wallmasters in the Palace of Twilight. You can stun it with your Bow and Clawshot, but you can't kill it and it will KEEP COMING FOR YOU AS LONG AS YOU HOLD ITS SOL. Although, it'll give up after you go to the "outside" area and place the Sol in the ground.
The cursed bokoblins in Skyward Sword are described as returning from death by way of sheer hatred and will to mess up the world. And, supposedly due to a penchant for undergarments...
A more traditional example in Skyward Sword: in the Silent Realm, there's two sorts of guardians; land based and flying. The land ones are faster and carry larger weapons, but they only pursue you when you're within a certain range. The flying ones, however, will never stop hunting you. They know where you are at all times and can phase through solid objects to hunt you down. They'll just keep following you until they eventually corner you.
Zouken Matou from Fate/stay night. He actually gets 'killed' so often and eventually so effectively by Kotomine that he moves his soul into the Crest Worm that was in Sakura's heart, at which points she rips it out. Then crushes it. And he's still not dead. Also Kotomine, who had his heart ripped out and was still around two days later to kick Shirou's ass despite the latter's body currently turning into swords.
Jedi Academy has four levels that involve different variations of the theme of an enemy (or several) chasing you that can't simply be killed, and three of the enemies fit this trope.
The rancor. If you actually want to kill it, it's harder than many boss battles... and when you do kill it, another one replaces it. So you'll end up avoiding it anyway. Its powers of following you are less impressive, as it gets lost and can't fit under doors.
Boba Fett. He's opposed to the idea of your finishing your mission, so he'll pit his Badass Normal powers against your Jedi ones at every turn, only to fly away if you manage to damage him enough and return soon after returning to full strength.
And finally, the mutated rancor. It's practically Godzilla, and it's completely immune to damage, so it's actually The Juggernaut as well. Breathing poisonous gas and flailing at things, it will follow you all over the complex in the level, its steps making the floor quake, and demolish the scenery and eat the badguys who released it when it can't find you. When you find a way to sneak into the next hall through an exit it can't fit through, it will bang the wall until it yields and resume pursuit. At the end, you'll be able to kill it by crushing it on a conveyor belt between a giant crate and an energy field that only lets giant crates through.
Jaden Korr: "What did I ever do to him?"
The InfocomInteractive Fiction game Leather Goddesses of Phobos has your henchman Trent (or, depending on a choice you make early in the game, Tiffany), who continuously dies in very unlikely ways and pops up again a few dozen moves later with an even more unlikely explanation for how he/she survived.
From Supreme Commander, is the Galactic Colossus, which without appropriate countermeasures is exactly this as it marches through your base. So is a Monkeylord if you're unprepared.
You as Rubi in Wet, you will regularly tear through rooms stacked to the brim with Mooks and survive. A more pure example is the ending, where Pelham sicks his pet Albino Tarrantula on you. After you kill her, you come after Pelham and he tries shooting you, it doesn't work and you behead him.
The Wizard of Yendor. He's certainly killable, but that doesn't stop him from coming back to torment you all the way through the Elemental Planes, steal the Amulet of Yendor and create copies of himself to help with this.
Bryan Wilks from Fallout 3. He will chase you across miles of post-apocalyptic wasteland, swim through mirelurk-infested waters, absorb unlimited amounts of gunfire courtesy of his Infant Immortality, all just to tell you that "things" are out to get him. And that his town has been overrun by giant, fire-breathing ants.
By extension, all Fallout 3 children (without mods), as they are unaffected by any and all harmful effects. You can shoot a Mini Nuke at them and they won't even blink, but any adults standing nearby will be well and thoroughly gibbed.
Llednar from Final Fantasy Tactics Advance recieves no damage at all if you try to attack him with anything. It was actually because of the "Fortune" law, so Ezel created an antilaw card, making Llednar vulnerable to any attacks.
Similar to the Metroid Prime example above, the eponymous heroine of Iji winds up viewed this way by the enemy troops, according to their logs - whether or not you're playing a pacifist run.
In the MMO Ragnarok Online, the Monk character class gets access to the skill "Steel Body", or "Mental Strength" in one translation, that cuts all damage, magical or physical, to 1/10 if you have no vitality or intelligence, and if those two stats are high, any attack will do ONE damage! Another class (the Tank furthermore) has a skill that does big damage in an area, but returns some to its caster. But a glitch can be exploited to make it HEAL you instead, thus doing huge damage to your foes while filling your own life gauge back up. In either case you get a nearly unstoppable character.
Ashley Riot is a Riskbreaker, a group of agents infamous for working alone, having a high mortality rate, and generally doing Parliament's dirty work. Ashley is the best of them. He's the hero of the story, and his enemy has immense respect for him.
Sydney: So this is a Riskbreaker. Most men complacently accept "knowledge" as "truth". They are sheep, ruled by fear. But you are different. Always calm, detatched. A smooth flow of thought into action. Indeed... it is almost as if... as if you had no soul.
There's a good reason he's in the page quotes for One-Man Army.
Wild Dog from Time Crisis. He must have taken at least a million bullets to all parts of his body and survived four self-destructs, three of them his own doing. And yet, he's always back for more.
Alex Mercer, and he's on a Roaring Rampage of Revenge all across Manhattan. He survives being torn to pieces in the blastwave of a nuke, regenerates From a Single Cell by absorbing nothing but a crow, and states that his work is almost done. Not done. Almost done. Imagine being the guys assigned to take him down. Over the course of the game, he murders his way through what has to be three-quarters of the marine forces — by way of kicking their helicopters out of the sky, tearing their tanks to shreds with his bare hands, and ripping apart entire bases — and comes out no worse for the wear. He is the Implacable Man. And he makes sure they know it.
Alex:NOTHING CAN PROTECT YOU FROM ME! NOT MEN! NOT WEAPONS! NOT ARMOR!"
Whether he's aiming for you or not, it generally seems like a good idea to flee from a man whose very existence tends to incite bloody battles to the death that often rage across multiple streets in a frenzy of blades and blood. You might not be his target, but you should probably get out of his path. You should start running if you see Alta´r, but...chances are you won't see him until he rams a metal spike into your neck.
The same goes for his Identical Grandson (a few hundred years removed) Ezio from the sequel. The man fights his way into the Vatican, merrily slaughtering the Pope's personal guard as he goes. He then shrugs off a blast from said Pope's Magi Tech staff (which incapacitates the other dozen or so people present), engages in a Magi Tech Wizard's Duel with said pontiff, is STABBED IN THE GUT by same, before sucking it up and going on to beat the aforementioned most powerful man in Europe to a bloody pulp with his bare hands.
Harbinger is relentless, focused, and entirely devoted to killing you, personally. Since he's remotely controlling the Collectors, he has no problems with letting you kill his current form and possessing the next one. In his own words, "I WILL FIND YOU AGAIN."
Then in the DLC, Lair of the Shadow Broker, there's Tela Vasir. She gets tackled by Shepard out of a four story window, gets in a really nasty car wreck, loses an enormous amount of blood, gets slammed in the face by a flying table yet she still provides one of the toughest (and most awesome) fights in the entire series.
The Shadow Broker himself probably counts. He fought you for a bit, got bored, and decided to activate his own personal shield, forcing you to hit him. he only dies when Liara dumps a load of plasma on his head.
Shepard him/herself probably counts given how many cybernetic enhancements and upgrades have been put into his/her body over the course of the game. Probably best illustrated during the Arrival DLC, when Shepard overcomes sedation and an army of guards to deny the Reapers once again. Lampshaded during the main game by Garrus pointing out that the Reapers killing Shepard only meant pissing him/her off.
Zaeed Massani survived being shot in the head. At the end of his loyalty mission, an enormous beam falls on his leg, which doesn't seem to affect him. He also killed a Krogan and all his Mooks.
Zaeed: Rage is one hell of an anesthetic.
Garm, the Krogan in command of the Blood Pack on Omega probably qualifies as this - Garrus remarks on how quickly he can regenerate his health. In the end, it takes Shepard, Garrus and two other members of Shepard's crew to kill him.
Krogan in general. More pronounced in the first game where they would get back up after death unless killed by ammo that caused disintegration.
Selvaria in Valkyria Chronicles is this when her Valkyrian powers are activated. No attacks you fired at her did any damage. When she showed up, your only option was to make your units take cover and hurry to finish the objective. Even when she isn't a Valkyria, she's still pretty powerful.
The King Tiger Tan in Company of Heroes. Its armor is so thick that no allied tank can penitrate its frontal armor. It has a really powerful gun, multiple machine guns, and max veterancy. The only way to defeat it is to surround it with multiple tanks or to use its natural enemy in real life, bridges. Destroying a bridge with demo charges will oneshot it, just like anything else. There is a reason why calling this into battle is the last ability recieved on the  terror doctrine commander tree.
The lesser known agdpanther tank destroyer is also a bitch to kill.
The Beast from inFAMOUS is a huge monster in the shape of a man seemingly made of lava. The military can't stop it, it just blows them into dust and keeps walking. Cole, the Electric Man himself, can't stop it, it just gets right back up after being hit by a storm of lightning called down on it from the sky. A nuke going off in its face can't stop it, it just reassembles Doctor Manhattan-style. The only way to kill it for good is to kill every Conduit on the planet.
Most of the colossi in Shadow of the Colossus qualify for this, with the only exceptions being Avion and Phalanx. Once the others have spotted Wander, they will not stop trying to attack him until he becomes physically inaccessible, dies, or kills them. Particularly notable is Dirge, which is reputed as being unique in that it is the only Colossus who seems to genuinely hunt Wander in order to devour him rather than just try to kill him. In fact, the reason Dirge's unnervingly large eyes are always orange is because it is one of the few colossi who is constantly attacking.
The Death spell in Sacrifice summons The Grim Reaper temporarily, who is treated by the game engine as a spell effect and not a creature; he cannot be targeted, shielded against, blocked, halted or damaged in any way, and will not stop hunting his target until he has killed it. If Death targets one of your creatures and you teleport away with it to the other end of the map, Death will immediately realign his course and slowly start following, ignoring everything else in his path.
Subverted with X-ATM 092 from Final Fantasy VIII. Despite its self-recovering system and its ability to ambush you during an escape from Dollet in a limited time that make you think you need to run, this giant spider can be destroyed for real, and you're encouraged to do so because of some extra See-D ranks. You just need enough firepower to blow it up before it can fully recover itself.
The protagonist of neverDead. Dismember him, run him over, or pierce him through. He never dies.
Asura, patron saint of Unstoppable Rage. He gets killed four times, and every single time he escapes the underworld, even angrier than before.
In Mann vs. Machine mode, some of the harder rounds feature a Super-Huge, Super-Strong, Super Unstoppable Robot—they can only be knocked back by the Heavy's Rage powerup, and will simply walk over any obstacles that they can't immediately destroy.
In Minecraft as long as healing crystals are intact, the Ender Dragon is unstoppable. If placed in overworld, it can fly right though anything that's not Obsidian, End Stone or Bedrock. Still feel secure in your cobblestone home?
Aveline from Dragon Age II is the game's resident Stone Wall. In addition to the usual warrior skills, her special tree has skills which make her immune to every status effect in the game, including critical hits. After taking enough of this, the only thing that can stop her is magically lifting her from the ground and confining her in a telekinetic prison, and she has better-than-even odds of saving against it. An illustration: in a contest between Aveline and a charging Ogre (read: horned sixteen foot wall of muscle), when the two meet, Aveline will still be standing. The Ogre will be on the ground.
In Dragon Age: Origins, the Arcane Warrior when built correctly becomes a virtual god. With right spells and a good armour, they will takes practically zero damage against most enemies, even High Dragons. The rest of your party may be dead, including your tank, but Arcane Warrior will keep fighting. If you also give him/her Spirit Healer as a second specialisation s/he will be practically immortal.
The Warden is seen as this by many of their enemies. An amusing example comes in the expansion Awakening, where as the new Arl of Amaranathine, one of the nobles beseeches you to rescue his daughter who is being held ransom by bandits. Upon arriving, the Bandit leader is irritated that her father didn't come himself as they planned to kidnap him and is utterly confident in simply taking you hostage instead... right until you mention you are the Commander of the Grey. Cue most of the other members of the gang soiling themselves that they're dealing with the person who killed the Archdemon. The more Genre Savvy of them simply decide to flee in terror, the ones Too Dumb to Live decide to take their chances... and one prefers to jump off of the nearby cliff to his death, rather than face you!
In Knights of the Old Republic, Darth Malak sets the entire Star Forge against the protagonist, sacrificing thousands of his own men with the sole intention that it might potentially slow them down. Part of the reason such overkill is justified is because he's facing an amnesiac Darth Revan, his former Master.
Darth Sion from the sequel, who you can only kill by convincing him that his life isn't worth living. According to the KOTOR Campaign Guide, Sion was once a living man, filled with so much hatred that when he finally was killed, his hatred and strength in the dark side allowed him to keep living, AND kill his assailant RIGHT THERE ON THE SPOT. He is bound together purely by his hatred. Oh, also, according to the medical records aboard the Harbinger, his flesh has been cut into a bunch of rotting chunks that now make up his body, and and each of his bones has been absolutely splintered and pieced back together.
Assassins can become this in PvP matches of Guild Wars when they use their Shadow Form enchantment. It makes them completely invincible to every attack or spell in the game. If an Assassin using this skill targets you in a match, your only option is to run. Unless you have a signet that can remove enchantments...
In Far Cry 3 Jason Brody makes just about everyone who isn't on his side assume that he is invulnerable because Vaas' otherwise lethal bullet was deflected by a cigarette lighter. Naturally, everyone who knew about Brody's apparent death jumped to the extremely logical conclusion that he just came back to life.
"The thing is... alright, the thing is: I killed you once already... and it's not like I am fucking crazy."
— Vaas Montenegro
Technically Brody does fulfill this trope, as Vaas foiled his attempts on revenge three times: first by shooting Jason, second by kicking him into deep water tied to a cement block, third by stabbing him with a machete. Brody survives all of them and manages to kill Vaas (just a few minutes after being stabbed), where he (finally) falls unconscious and presumably nearly dies.
The Inspector and his dog in Subway Surfers: No matter how fast or far you're running, no matter how big a lead you get, thanks to a jetpack or mega-headstart powerup - one stumble and The Inspector will appear right on your heels.
As an anti-piracy measure, Serious Sam 2 will set one of these loose on you if it detects a pirated copy of the game: An indestructible lightning-fast giant-scorpion creature will follow you from practically the start of the game. It can't be killed and it's too fast to escape from for long. Of course, this merely spawned a sub-set of players who seek out pirate copies just to see how long they could last against the beast.
The Crooked Man will never desist from chasing David until the good ending of the game is reached. He can't be killed before then due to already being dead.
In Privateer, later in the game when you find and equip the discovered Steltek gun on your ship, a Steltek drone will appear at random and attack only you. Your weapons won't scratch it, and although you may give it the slip using jump points, it will eventually show up again. You only finally get the ability to kill the drone just before the final mission when an actual Steltek comes along and charges up the mounted Steltek gun to give it the ability to harm the drone.
StarCraft: The Torrasque. A special, one-of-a-kind super-Ultralisk that just gets reincarnated back at the base when it's killed, over and over and over again. It makes a return in Starcraft II: Heart of the Swarm as a possible mutation for all of Kerrigan's Ultralisks: the ability to revive once upon death.
O-chul ''nearly'' does this in #542, in which he, in order, throws one of his hobgoblin captors into an acid-tolerant shark's cage without using his hands, stabs himself using the spikes at bottom of said cage (filled with acid) to free himself from a rope bond, gets caught by the shark but pushes himself out, then tricks the shark into grabbing him so its momentum can throw him out of the tank, and still has enough "oomph" left in him to rush at Big Bad Xykon while drawing back a fist... at which point Xykon uses the weakest of the spells in his Functional Magic arsenal to push O-chul into negative hit point territory, which causes him to finally faint. He's still pretty good though, given that by the look of the scars on him, O-chul has probably gone through similar Death Traps multiple times, and Xykon's parting comment seems to suggest that each time he's gotten as far as rearing back for the punch. Justified, despite O-chul being a Badass Normal, in that the comic holds to the Dungeons & Dragons game's use of Critical Existence Failure.
Previously, O-Chul took a hit from a Disintegrate spell while running directly at an enemy...and didn't miss a step. Earlier in the series, a single Disintegrate was enough to stagger a freaking dragon. (Two reduced it to dust.)
The dialogue from the earlier strips also implies that Xykon is also implacable - being a lich (and thus a skeleton), he is invulnerable or resistant to most physical attacks, and if he were to die, his phylactery allows him to generate a new body. Subverted in that the only time he is destroyed is when Roy attacks him with his bare hands (though the Phlebotinum in the room did the actual destroying).
From Girl Genius, perhaps only three words must be said: THE UNSTOPPABLE HIGGS!
Well, heendedupstopped anyway. Still pretty badass. The key point here is that when an Action Survivor reaches Implacable Man levels he's going to require "Rum, lots of Rum" after it's all over.
At a later point he was thrown into a wall by a robot. The one left damaged was the wall.
The Mecha Easter Bunny from Sluggy Freelance. A rabbit Terminator with a built-in arsenal of guns. Survived a bazooka blast to the face from Bun-bun with only a lost nose. Was, however, distracted by having to hide Easter Eggs.
Bun-bun himself, though not invulnerable, fits this trope through the sheer power of Bad Ass.
Captain Blacksoul from Oceans Unmoving. Followed Bun-bun so implacably he was said to be the only thing the rabbit feared. It turned out there were very good reasons for this...
Oasis. She can take a lot of damage before dying, and when she does, it only slows her down for a moment. Has specifically stalked Torg and ZoŰ as a major plot point that has lasted for years. Kusari would be the same if she were sent after you.
Sarda from 8-bit Theater. In the end, he was taken down only because he absorbed too much power and blew himself up.
Hilariously averted near the strips end,where the Dark Warriors are holding the four elemental orbs,threatening Sarda, who then points out that they have no idea how to use them. Bikke beans him with the Orb of Water, knocking him down, making Bikke the only one to really harm Sarda in the entire comic. Sarda responds with You Will Be Spared.
Chelsea Grinn of Chimneyspeak, to the point that armies can't take her down.
Chelsea: Bullets don't work on me, little man.
Jones in Gunnerkrigg Court led the Court staff trying to catch Jack while he was infected with Whitelegs. After recovery, he appreciates efforts that saved his sanity and probably life... but still finds Jones scary. Apparently the enigmatic calm petite lady as unstoppable as the Terminator and as perfect as Mary Poppins (she can deflect sword with her face and crumble concrete like soft cheese) made a lasting impression.
Mr. Blank from Sam and Fuzzy. Provided it's not a comedy strip, and provided he wants someone, he isn't getting stopped. When Fuzzy at one point distracts Blank by throwing what he wants off the eight story of a building, Blank jumps after it without hesitation. When Fuzzy subsequently looks over the side and fails to find any body at the bottom, his companion's comment is "He's a blankface, it will take a bigger fall than that to kill him."
You can break his knee with a crowbar. You can have him impaled through the chest with a trap that is explicitly stated to be lethal. You can blow him up with a bomb that collapses several rooms. No matter what you do, Ace won't stop coming to get you...
The trailer combines huge amounts of Rule of Funny. It's shown that the Horribly Slow Murderer simply will not die (even to several gunshot wounds in the chest), and has dozens upon dozens of spoons stored in his coat, in case the victim tries to knock away or break his spoon. When he runs to the nearest police station or ask his friends for help, the guy disappears and nobody believes him... until he's alone again.
The Slender Man is said to have these traits; in Seeking Truth, this is canon. He's implied to take a shotgun to the chest, not very long after he takes several handgun bullets to the chest.
Atop the Fourth Wall has Lord Vyce. He walks through Linkara. Linkara was at this point almost entirely undefeatable, only losing once early on in Kickassia. Then again Linkara had no Zeonizer and no Iron Liz, but he still takes down Pollo in seconds, kills Pyramid Head, and takes Linkara's BFG at full strength with no damage at all. Linkara only manages to keep from dying by stealing his weapon and hitting him with it, with Vyce leaving seconds after being shot by it, Linkara being left bloodied and half dead. And then he came back in Pollo's body and is still a threat who nearly drove his ship into the Earth. Odds are good that he's still out there, fully believing that the Entity is still alive. He then returned yet again by taking over Linkara's ship.
Red vs. Blue Has The Meta aka Agent Maine who, even without his powerups, is super strong, super fast, gets stabbed, shot, beaten, wrestled, slashed, blasted, blown up and impaled. And STILL keeps coming. It takes a 400 foot drop off of a cliff into frozen waters to kill him.
Parodied on The Simpsons, "The Boy Who Knew Too Much": Bart, on the run from Principal Skinner for truancy, cuts a rope bridge across a raging river. Skinner, maintaining a deadpan expression, marches down into the river, disappears under the water, and reappears when he surfaces on the other side. Bart exclaims, "He's like some sort of... Non Giving Up School Guy!" The scene is a direct parody of Westworld.
In a flashback sequence, it's shown that Grandpa Max stuck him to a nuclear missile, shot the missile into his spaceship, and presumed that was the end of it... until the season finale, where Vilgax emerges from his regeneration tank. At the end of the episode, he winds up, again, getting blown up with his ship.
He resurfaces at the end of season two, at the end of which he's left trapped in the Null Void, an alternate dimension.
Season 3's premiere episode has Ben time-travel to the future, meeting a future version of himself who had torn Vilgax to bits. However, he then gets brought back to life by another recurring villain, who winds up taking a back seat to Vilgax for the rest of the episode.
Ben lured Vilgax to the sewers where his dad (Who had recently learned Ben's secret) lit a flammable substance and, after Ben turned into XLR8 and got him and his dad out, Vilgax was left to be caught in the fiery explosion.
Jonny Quest: The Real Adventures had Ezekiel Rage, an apocalyptic preacher who's supposedly been killed after each of his attempts to end humanity, only to return good as new. In his first appearance alone, he survives a horrific fiery car crash that kills his family, setting him on his villainous path. Even being aboard a space station that re-enters the atmosphere until it breaks up, the remains plunging into the open ocean, doesn't do him in. It took sending him back to prehistoric times and leaving him at ground zero of a nuclear blast before he was finally considered dead.
Rampage from Transformers: Beast Wars, who is only held in check by Megatron because Megatron has the power to torture his soul if he steps out of line. Without this it's quite possible he'd simply torture, murder, and eat everyone on the planet. Frequently subject to The Worf Barrage. It's the same with Lugnut in Transformers Animated. Especially if it involves GLORIOUS MEGATRON.
Optimus Primal temporarily becomes this in the Beast Wars episode "Gorilla Warfare", when he's infected with a berserker virus. Efforts by the lower-ranking Predacons to stop him are dispensed with in brutal fashion.
Brock Samson from The Venture Bros.. Slamming a car into him only pissed him off even more, driving over him in a bus knocked him out for a bit, but he still got back up more pissed than hurt. Even exposure to the vacuum of space had little effect.
Season 5 of Teen Titans features an Implacable Woman: Madame Rouge. Like the T-1000 in the Terminator films, it takes her only a few moments to reconstitute after being frozen and shattered into pieces.
Slade in the Teen Titans fourth season after having become The Dragon to Trigon. He shrugs of all attacks (except for Raven's magic) like they're nothing, even snapping his neck back into place after Robin breaks it. He was undead at the time.
Avatar: The Last Airbender has the Combustion Man, who won't stop his assassination attempts even when the person who hired him tries to call the hit off. On his first appearance he just blew up everthing that was thrown at him. He also seems to be pretty damn Made of Iron as he shrugged off a barrage of ice-shards and both a rock and a boomerang hitting him in the head (however, said head injuries did make his power backfire and lead to him blowing himself up).
Also, Azula, Mai, and Ty Lee, during the episode "The Chase."
The Avatar State. During the finale it punches through everything Ozai throws at it, demolishes about 50 giant rock columns and generally kicks ass without stopping, slowing or even noticing anything that would have instantly KO'd anyone else who tried to do the same.
In the Sequel Series, The Legend of Korra, when Tarrlok attempts to bloodbend him, Amon simply powers through it and keeps on coming. Then only a minute later, Korra sends ice-spears directly at him and he doesn't even break his stride as he weaves through them, coming for her.
And then there's the season finale, where he comes off like a villain from a slasher movie, complete with Menacing Stroll.
As seen in old-school Looney Tunes, the little man from the Draft Board will not be deterred under any circumstances.
In SWAT Kats, the Metallikats constantly shrug off most attacks on them. In their debut episode, they were particularly formidable, walking through gunfire and ignoring the Swat Kats' best attacks.
In the Tom and Jerry short Dr. Jekyll and Mr. Mouse, Jerry is turned into one of these by a concoction that Tom has force-fed him in an attempt to poison him; Tom tries slamming down on him with a phone book, hitting him repeatedly with a fire poker, shutting a door on him, and locking himself in a safe, all to no avail.
Batman: The Animated Series has a good guy version of this with Batman in the episode, "The Underdwellers". First, one of the sewer kids tries to elude Batman through the tunnel system he knows like the back of his hand, only to find to his shock that The Batman is waiting for him. The Sewer King gets his own surprise in a quiet moment when he thinks that he has eluded Batman and locked the door behind him, only to suddenly have it blown open seconds later as he realizes that the Dark Knight is after him and will not stop.
Elmyra from Tiny Toon Adventures. Nothing can stand between her and anything unfortunately cute enough to catch her attention. At one point, a sea monkey pulled a plug at the bottom of the ocean, which ended up draining the entire universe in order to get away from her. She still caught him.
Adventure Time's Ice King places a hit on Finn and Jake intending the hit man, The Scorcher, to hit them, "like on the shoulder or something". Anyways he has trouble getting the Scorcher to stop hunting them down. He does by tricking the scorcher into thinking Finn and Jake dead
Rasputin The Mad Monk, whose... well... Rasputinian Death is something of a legend. To them it was assassination; to him it was an induced nap. See the film Rasputin: Dark Servant of Destiny if you want to see James Frain take about five minutes to kill Alan Rickman. Even better, see Nicholas and Alexandra where Rasputin is played by Tom Baker.
Life itself. We've found anaerobic microbes inside volcanoes and sulfur springs and plants that live in the arctic. There will probably be rats and cockroaches after we blow ourselves up. Life finds a way.
Robert Henry Cain. During the battle of Arnhem, he took to destroying tanks with gusto, hip firing a 2 man Piat gun and destroying several tanks until a charge blew in the barrel. He was severely wounded, but refused morphine and returned to the tank killing, and when he ran out of ammo for his Piat, he began using a 2 inch mortar instead. His eardrums burst from the constant explosions, yet he continued attacking tanks with a mortar at point blank range. He was awarded a Victoria Cross for his actions.
Properly speaking, there was no battle at the town of Zwolle. What there was was one extremely ticked off man with a sack of grenades and a jacket covered in machine guns routing the entire German garrison (including the Gestapo members who escaped being shot down or blown up when be kicked down the door of their local headquarters, sprayed them with machine gun fire then tossed in some grenades for good measure). He was supposed to be scouting the German defenses so that the Canadian artillery knew where to shoot, but he and his partner (the one who got killed before he tap-danced on the garrison's faces) got ambitious and decided to capture the town themselves so that it didn't have to get pounded into rubble.
Humans in general. We are one of the few species that can hunt prey by chasing it to death. It's a practice called Persistence Hunting. Our two-legged gait is higly efficient compared to quadrupeds, and we have excellent heat-regulation systems (sweating), not to mention extremely dense muscles (an adult male human weighs about as much as a jaguar).