Healing Factor



"Wolverine: I've survived five different wars in my lifetime. Comedian: That's really nothing to brag about when one of your powers is not dying."

- I'm a Marvel And I'm a DC, "Wolverine and Watchmen"

A character is hard to kill, not because he doesn't get hurt, but because he has the ability to rapidly recover from serious damage. While it depends on how fast he can heal and how much of a beating his body can take, a character with healing factor will bounce back from severe injuries that other beings can't, often with no scars or medical treatment.

Slightly more plausible than being Super Tough or Nigh Invulnerable, as it is a souped-up version of a power certain real life forms possess. When this ability is powerful enough (such as regenerating from being reduced to almost nothing), it actually becomes a form of Nigh Invulnerability, however. Rarely will a character need to worry about infection, as a super immune system is most often packaged in, but they may need to worry about setting broken bones.

Really powerful characters will be able to regenerate lost body parts. Ridiculously powerful regenerators may be able to recover From a Single Cell in a stain on the floor. Most often, loss of the head or brain injury is the only permanent damage, and even then they may come back just missing some memories or with an altered personality. Sometimes they appear to be dead for brief periods, but that's just the regeneration taking a while to deal with unusually severe damage.

On the down side, extreme regeneration often leads to the character getting targeted by The Worf Barrage so often, people go "Good Thing You Can Heal" because their Immortal Life Is Cheap. Also, regenerators are often more Made of Plasticine than the rest of the show's cast.

Note that if any real-world life form were able to recover this fast, they'd need a reserve of raw organic material to work from, and afterwards would be very hungry. The only way to justify always repairing the exact amount of flesh damaged is if it uses the actual damaged flesh to do it. Writers who acknowledge this often at least have their regenerator out of commission for some time, resting and feeding... or harvesting limbs. The effect may be compared to the rapid cell growth, differentiation and self-organization of human embryonic development if the writer is interested in any degree of scientific plausibility, but most don't bother with even that much Hand Wave; they just have the wounds close up and new tissues and organs appear. Depending on the strength of the regenerator, they may also be a practical Perpetual Motion Monster, able to go for months or years without food and water since their healing factor keeps their body alive... though this sort of Immortality Hurts.

Reptilian characters, taking a cue from real-world lizards that can shed and re-grow their tails, are likely to possess at least a minor form of this. Dragons, werewolves, and vampires sometimes have it as well. Other Shapeshifting characters may have this packaged in with their powers, though it's often described as returning to their "default" form rather than regenerating. Nanomachines are a common justification for an acquired power by otherwise human characters in a technological setting.

If regenerators have an Achilles' Heel, it's most often a nasty one: either suffocation, decapitation, poison, gas, fire, ice, or acid. Other times, the weakness is similar to Clone Degeneration, each re-growth results in Harmful Healing and increasingly damaged appendages/organs/shorter lifespan.

An in-universe, as opposed to plot-based, version of Hollywood Healing. Doing this to others is Healing Hands or using a Healing Potion.

If a character can be blown to bits and reform you could be looking at Pulling Themselves Together. If it happens offscreen, this may be the explanation for an Iron Butt Monkey. If this appears in a video game without an in-story explanation, it's Walk It Off.

Also, its more properly called an Accelerated Healing Factor; "Healing Factor" simply refers to how quickly you heal- normal humans, for instance, have their own healing factor: a normal one. This is in fact what it was originally called in comic books and elsewhere; "Healing Factor" emerged because its, well, shorter.

Anime & Manga

 * Loosely implied to be a vampire's source of immortality in Rosario + Vampire. Their blood has a powerful regenerative effect on anyone, which Tsukune is quick to demonstrate once this is introduced.
 * In Ichiban Ushiro no Dai Maou, Sai gets an arm chopped off. The stump sprouts a new one, out of blood, which regenerates back to a regular arm in seconds.
 * The eponymous warriors of Claymore are classified as Offensive or Defensive types based on their youki. Generally speaking, Offensive types can reattach recently severed limbs while Defensive types can grow new ones. As Awakend Ones become more common, this often results in Defensive types aiding the Offensives in Pulling Themselves Together mid-battle.
 * Most of the major characters of Hellsing, and the Nazi vampire Mooks that show up later in the manga, have impressive regeneration abilities; Alexander Anderson, for example, can take several headshots in rapid succession and keep fighting. Every single one of them is put to shame by Alucard, though, who allows himself to be near-liquified at the beginning of several fights just to completely demoralize his opponents before brutally killing them.

Schrodinger probably takes the cake; it's implied that his ill-defined ability to be everywhere and nowhere lets him ignore any injury, and he shrugs off having his head splattered by an extra-large anti-vampire bullet. "Inuyasha (to Sesshoumaru): 'You just stay back! This is no place for an injured person!' Jaken: 'What's that?! Just whose fault do you think it is that it came to this?! It's solely because that Sesshoumaru-sama has...' Inuyasha: 'Shut up!' Thinks: 'I know that.   Sesshoumaru wouldn't have been wounded to this extent...' Sesshoumaru (to Magatsuhi): 'Hmph. You despicable creature. Making me receive pity from the likes of a hanyou...' Jaken: 'Oooh! He closed his wounds with pure fighting spirit! Nothing less from Sesshoumaru-sama!'"
 * Schrodinger's case is more a rejection of state than actual healing, of the 'he was never there in the first place' variety.
 * Deoxys in the seventh Pokémon movie is depicted regenerating a vaporized limb. In fact it can regenerate its entire body as long its crystal core is intact.
 * The Wu from the manga and anime 3x3 Eyes are people who have had their souls extracted by an immortal Sanjiyan Unkara and kept within the Sanjiyan. As long as the Sanjiyan lives, the Wu cannot be killed or destroyed- by anything. Their healing factor is so great that main character Yakumo once regenerated from being chewed into tiny scraps by a giant demon in a matter of minutes, although they can't regrow limbs if they're separated from them.
 * It's not sure if they're actually unable to re-grow them, it might be a bit more complicated. The one time where an Wu was dismembered without re-attaching it instantly after the fight, the arm was kept in an sealed container. However, that might have been just to keep the arm from moving, after all, Wus can still move their body parts even if they're cut off.
 * When the container shattered and (more important) the seal on it, Yakumos arm instantly started to grow back, informing him something was going wrong. And in the mange, he almost regularly loses his limbs and regows them (often resulting in him losing his combat gloves).
 * Abel from Trinity Blood has been shown regenerating a lost arm (from the leftover pool of blood) after it was blown off.
 * In the third episode of Haré+Guu, Guu regenerated her arm. After chopping it up and eating it.
 * C.C. from Code Geass, who can recover from fatal injuries (such as a bullet to the brain or heart) in a matter of minutes. A few episodes imply that she might be near Wolverine in terms of regeneration: And for all this, the only mark she bears is a very deliberate-looking scar under her left breast.
 * In the Audio Commentary, when the staff and cast discuss C.C.'s powers, voice actress Yukana jokingly suggests probably the cutest version of a Healing Factor ever: that when C.C. is killed, her body breaks apart into several miniature C.C.s that run together to re-form her original body
 * The guro h-doujin Mai-chan's Daily Life involves sex slaves with the ability to regenerate from virtually any injury, no matter how debilitating, mutilating, or fatal. Furthermore, unlike most of the above examples, some of them also have the ability to convert pain into pleasure, thus literally "getting off" on the sick, sadistic things their clients do to them almost as much as said clients do. Fortunately, they are almost always unable to bear children. If one of them does have a child, that kid won't be born with the trait, needing to develop it as it matures (though it's hinted that the powers kick in at a fairly young age).
 * This is Rin Asougi's only power in Mnemosyne. Unfortunately for her, this means she loses fights quite regularly, with fatal results. Seeing as how she can only permanently die from being devoured alive by a specific monster or having her 'time spore' pulled out by a specific person, this isn't quite Blessed with Suck.
 * Busou Renkin - Ikusabe, one of the alchemic warriors employed by the Regiment. His Busou Renkin, Gekisen, not only arms him with a triple-bladed spear, but it also concedes him and his weapon regenerative abilities, all the way from the atoms. He manages to regenerate his body completely even after Papillon blows it up completely!
 * Chirico Cuvie from Armored Trooper VOTOMS is called an "abnormal survivor," and has the capability to not only survive normally fatal physical injuries and illnesses, but to resist damage from certain types of injury, such as being burned alive by mecha fuel. However, as a negative side effect of this, he suffers extreme mental stress from all of the fatal injuries he has taken, to the point of being more or less outwardly emotionless. His early memories include being burned alive and shot through the heart.
 * Manji from Blade of the Immortal
 * Subverted in some aspects in Naruto: Tsunade and Naruto can regenerate from grievous injuries very quickly, but they do so via rapid cellular growth, which ages their bodies prematurely and shortens their lifespans (which actually happens). Also, Naruto tends to pass out and become famished regenerating anything more than minor injuries. "No matter what the injury is, one night of sleep has always been enough."
 * Played straighter with Orochimaru though, who has survived being cut in half amongst other things and shrugged it off. He can even shed his skin which regenerates himself, giving the appearance of vomiting out a fresh body. He also can soak up an insane amount of blunt force trauma, far more than any normal character in the story.
 * He can do so without fear of shortening his lifespan because he regularly commits Grand Theft Me on others. It does however mean he burns through weaker bodies in just the three years he has before his transfer form can survive another transplant.
 * The primary effect of the "Cure virus" in Ever 17 is to give the infected party a healing factor that makes it impossible for them to be killed.
 * In Slayers, trolls have such fast regeneration abilities that they are nearly impossible to kill. The main character, Lina Inverse, solves this issue by
 * The Wolkenritter of Magical Girl Lyrical Nanoha. They may have lost the Rejuvenation Program, but they still have a Healing Factor that lets them recover a lot faster than a normal human. However, this has been getting weaker as time goes by, though thankfully for Vita, not so much that  could take her out permanently.
 * Two seasons later, and we're introduced to the Huckubein, who can regenerate even better than the Wolkenritter. Cypha proves this by regrowing an arm that Signum cut off. Oh, and they're also pretty darn tough too.
 * Also there's the fact that after said two seasons the Wolkenritter's Healing Factor has finally faded away.
 * Berserk Evangelions have his ability, ranging from regrowing shattered bone to . Angels have his by default, as all of them have S2 organs and couldn't operate alone without support units.
 * In Dragon Ball, Nameks like Piccolo regenerate as long as their vital organs are intact. Most later villains had this ability, but most have it in even greater strengths, including Cell, Buu, and Meta-Cooler (who can revive from a single piece of themselves), in addition to some of the evil dragons.
 * Majin Buu is the living embodiment of this. No matter how badly he is destroyed he can always regenerate as long as any part of him still exists.
 * Meta-Cooler also falls under a different trope.
 * Kanda in D.Gray-man has accelerated healing, but at the cost of some of his life.
 * Also Road, who can't be killed unless you know her "true form".
 * And Krory, who can heal himself by drinking Akuma's blood.
 * Yuki Nagato from Suzumiya Haruhi is able to regenerate using her Magic From Technology, apart from being seemingly unaffected by physical injuries. The limits are unknown, but it does happen in an instant.
 * The Homunculi from Fullmetal Alchemist all have this power. The Shapeshifter Baggage is somewhat justified by having the Homunculi powered by a Philosopher's Stone/a bunch of Red Stones (depends on the version), which converts energy into matter. When their stone runs out of juice, the Homunculi lose their powers & have to get it recharged (or run the risk of becoming Deader Than Dead).
 * Ranma from Ranma ½ recovers from injuries so fast some fans have theorized he has a Healing Factor. Witness him shatter every bone in his body and recover to full fighting capacity only a few moments later, in the middle of a fight.
 * "Full fighting capacity"? Later in the fight, he was buried under several tons of ice, punched through said ice, leapt around like a flea on acid, and was still able to run from a vengeful Amazon that very night without ever stopping to rest, and all that in his "weaker" female form. In the manga, anyway (where Shampoo's arrival took place immediately after the Ice Skating duel.)
 * Lampshaded early on: his agreement with Shampoo to "half-kill (girl) Ranma" (long story) didn't work because he instantly recovered after the massive beatdown.
 * The final enemy of the series, the Phoenix King Saffron, can generate limitless amounts of heat... which he uses to rejuvenate himself at will. He has had half of his body (head included) frozen solid, and the arm on that side broken off; as soon as the freezing influence was removed, he merely melted the ice with no damage to his brain and sprouted a whole new arm. He's not above tearing off his own wings and flinging them as deadly flaming projectiles, and having his entire body frozen and shattered only inconveniences him as far as making him regenerate a brand new infant body.
 * All of the characters (or at least Ryoga Hibiki and Mousse) have displayed something like this at least once in the series, if never quite in as impressive a fashion as Ranma.
 * On at least one occasion (during the first appearance of Shampoo), Ranma is beaten "half to death" by Genma and Soun, and looks to be in horrible shape. Akane says something that irritates him, and he pops upright, almost completely unhurt—which causes Akane to ask, "Weren't you beaten to a pulp just a second ago?"
 * The Immortals from the Mermaid Saga can regenerate from any wound, naturally, except burning to ash or having their heads completely severed.
 * The Guyvers from Biobooster Armour Guyver can regenerate their entire bodies if destroyed, so long as the control medal on their foreheads is not damaged. At one point, lead character Sho contemplates being a clone since his original body was killed.
 * In addition, Aptom develops a massively potent regeneration ability, still limited to available biomatter unlike the Guyvers, which he uses to great effect by splitting up in to clones and using one as a distraction.
 * Finally, any of the monsters created by Chronos could have damage regenerated by spending some time in a giant test tube.
 * Shikabane Hime in the show of the same name normally heal faster than humans, and can regenerate limbs given enough time. They can also have most wounds healed instantaneously by their contracted monk.
 * Immortals in Baccano!! get this standard with their Immortality. They also avert the Regenerative Baggage issue by using the damaged or spilled flesh and blood to patch up the wounds. Yes, even if their remains are splattered across the room, thrown off a speeding train, or (in the novels) burned into smoke. A special version of the elixir was made by Szilard and given to Dallas and his cronies which gives them just the Healing Factor but they still age.
 * Ulquiorra Schiffer of Bleach reveals that this is his special ability during the final stage of his fight with Ichigo.
 * It is actually an ability of many hollows to self-regenerate. Ulquiorria mentions that most of the Arrancar gave up this ability to become more powerful.
 * Aizen has this as well in his Butterfly form. Case in point:.
 * Kotaro of Mahou Sensei Negima has a Healing Factor as part of his ultimate demon form,
 * Negi can reform severed limbs in his lightning mode. This is because he turns his body into lightning, and therefore can't be permanently injured by physical attacks.
 * One of the "signature" abilities of the Deadman soldiers in Gungrave is the ability to regenerate/near-instantly revive from almost all injuries sustained. Beyond the Grave, the heroic Deadman of the series, has this ability because of the technology used to reanimate him and other Deadmen. Grave's weakness? His healing is powered by full-body transfusions of his (rare?) blood type. Lack of blood for a prolonged period of time results in him decomposing and slowly reverting back to true death.
 * Franken Fran has a story of a girl with a Healing Factor that reached Body Horror levels. See, not only does it replace lost arms and legs, but it keeps on creating new body parts even when she's perfectly healthy. The end result is a body with multiple faces, organs, limbs, and torsos growing out of it at once.
 * In Love Hina, Keitaro's immortality is expressed as being able to completely heal from the worst Megaton Punches and landings from said punches within a few panels. This is averted only once, when he gets his leg broken; that takes several chapters to heal, and the Hinata girls are amazed that it actually happened. Oh, and the reason? The giant decorative thing on the top of the university hall fall on him. And this only happened because someone said he used up all his luck.
 * Killy from Blame! has a very slow-acting Healing Factor. He can apparently recover from any damage, but it takes years, or even decades. Severed limbs take less time to reattach, which is fairly necessary considering the weapon he uses.
 * Soul Eater - People infected with the black blood can do this. Infection alone does not grant this, but deliberately using it does. It hardens to either avoid damage or stop blood-loss. Crona demonstrates both early on, as Soul Eater is simply unable to cut them. The healing side is shown when Crona is stabbed by Death Scythe, the injury also showing that the black blood is not impenetrable. The shinigami have a form of this. Kid's body suddenly started looking rather like his father's when he re-attaches the arm severed by Mosquito (the hand of which, come to think of it, was still holding Patti. Eww).
 * Minoru "Doctor" Kamiya in Yu Yu Hakusho can nullify his ability to feel pain and reattach his own limbs.
 * Not to forget the older Toguro brother, who can both regenerate and restructure his body at will, and will apparently survive any and all injuries as long as even a single cell of him is still alive.
 * In Durarara!!, Quarter-Dullahan has this ability. A comment made by Shinra while treating her wounds suggests that not only does (the entirely human. Supposedly) Shizuo Heiwajima have this as well, but that his Healing Factor is greater. If nothing else, it would explain how he's recovered completely from things like shattering his spine and pelvis or.
 * Tengen Toppa Gurren Lagann - Viral undergoes some form of bioengineering that causes him to stop aging and gives him a Healing Factor, making him effectively immortal.
 * This was given to him by Lordgenome, who achieves immortality by putting cells into biological stasis. He applied this to himself
 * Gun X Sword - This is one of the perks of being linked to one of the Original Seven armors (mechs). Unfortunately, the symbiotic link also means that riders need their armor to live (at least if they have had reconstructive surgery).
 * Madoka Magica: Sayaka gets this, as a result of her wish involving healing.
 * The monomakia from Brigadoon Marin and Melan heal rapidly, especially if they return to their ampules. The monomakia Cosmos can apparently confer a lesser degree of healing factor on its user, too.
 * Inuyasha: Youkai always heal much quicker than humans do and Sesshoumaru is tougher than most. At one point, he gets his one single arm torn to shreds resulting in him having to be rescued by Inuyasha. This results in the following exchange, which angers Sesshoumaru so much that he actually earns a regeneration upgrade that, by the end of the fight,


 * Then, there's Naraku. Being cut to bits is only a minor inconvenience to him.
 * In Tiger and Bunny, one of the less utilized advantages of - one that doesn't see use until the thirteenth episode - is the ability to accelerate the speed of his healing by a hundredfold. Unfortunately, this only means that (at the absolute most) he can give himself less than eight-and-a-half hours' worth of concentrated healing, which, as any doctor will tell you, is barely enough time to sort out the cosmetic damage, let alone the serious stuff.
 * Rin from Blue Exorcist heals from wounds pretty fast. Like, getting stabbed in the stomach only for it to heal in mere minutes? Arthur even
 * In Tokko, a healing factor is one of the powers gained by people with phantoms living inside them.
 * Kore wa Zombie Desu ka? Ayumu will heal from anything. It helps that he's already dead but he still feels pain and can be injured. When he leaps off a building holding a bomb the girls in his harem have to collect all his body parts and reattach them before he heals.
 * Inugami Akira of Wolf Guy Wolfen Crest has this on account of being a werewolf. During the full moon, he's night invulnerable.
 * Both averted and played straight in One Piece. Characters who have eaten Logia Devil Fruits appear to have healing factors. But in reality, they can just put themselves back together if they get cut while using their abilities. If they actually get injured, then they can't heal themselves simply by changing into whatever element they have. But then there's Marco, First Division commander of the Whitebeard Pirates, who actually does have a healing factor, thanks to eating a Mythical Zoan Fruit that lets him change into a pheonix.
 * from Cyborg 009.
 * Both Yukiko and Liselotte Werckmeister from 11eyes share the same immortality with rapid healing factor and undying. It is revealed that the Voidstone is the source of the immortality and separating it from the host will disable that immortality.
 * Quon of Towa no Quon has this as one of his abilities.
 * Akasha Bloodriver, one of the strongest characters of Rosario + Vampire has a very powerful healing factor that can cover up even the most fatal of injures.

Comic Books

 * Wolverine of the X-Men is the iconic Superhero example. This has been subject to extreme Power Creep, Power Seep; he went from "very tough, but can be killed by a single lucky shot from a Humongous Mecha" to "survive being at ground zero of a nuke". (He was also once regrown from a single droplet of blood that fell on a powerful Ancient Artifact once, but that was more a demonstration of the artifact's power than his own, and may have been hallucinatory anyway).

An arc in his main book was written to tone this down—by the same writer who had written one of the more ridiculous examples, ironically enough.It exemplifies Voodoo Shark - he could battle the Angel of Death if ever he dies in order to return to life, having beaten him before, but apparently can no longer do this.

There's also Wolverine's Opposite Gender Clone X-23, who has all of Wolverine's powers. Though the exact nature of her healing factor outside of Limbo has yet to be determined. It apparently has some limit. Wolverine's son Daken also inherited his fathers healing factor.

Finally, Wolverine's arch-enemy Sabretooth had virtually the same power-set, including the healing factor. But all that was cut to an abrupt end. Literally, thanks to Wolvie's anti-healing katana forged from the dark area of his soul.
 * Due to the nature of most children's shows, this can't be shown that effectively. The 90's X-Men animated show tries to, but it's best shown on TV in X-Men: Evolution when Wolverine is shown to have broken his legs from a helicopter jump, and later on in Season 4 when he falls out a plane.
 * Lobo from DC Comics has an absurdly over-the-top Healing Factor, as he is partly a Wolverine parody. Plus, neither afterlife wants him.
 * This is taken to such ridiculous extremes that at one point, one of his powers was that a single drop of his blood will grow into another Lobo.
 * In one story, Lobo was "killed" by having a very special bomb shoved down his throat. He exploded in a spray of crimson... only for EACH drop of blob to grow into a Lobo clone in a matter of seconds. The group of Lobos brutally murder the aggressor.... and then turn on each other, specifically murdering each other in bloodless ways, until only one remains. He announces that he is the true Lobo, and then goes off doing Lobo type things. It's implied that this happens regularly.
 * Painkiller Jane.
 * The Incredible Hulk has been at various times shown to have a healing factor that makes Wolverine's pale in comparison at times. (Including having all his skin ripped off and regrown in seconds—partly justified in that drawing mass and energy from another dimension is explicitly part of his powers.)
 * More specifically, the Hulk's healing factor is much like his strength level in that it's tied into his emotional state. The Hulk not only gets stronger as he gets angrier, he also heals faster.
 * Apparently, Hulk's healing is so fast that it took years for anybody to even notice it existed. He regenerates so quickly that nobody could tell that attacks could actually damage him to begin with.
 * Iceman could be considered to fit this trope - he once had a giant hole blown in his chest while in ice form. He was quite reasonably afraid of dying if he changed back but when he did it was as if the injury had never even happened in the first place.
 * Courier of Marvel Comics has the ability to regrow body parts, but can't create matter, so when he had to regrow a finger he shrank by one inch.
 * Deadpool from Marvel also has this (he even got it from the same place as Wolverine got his adamantium skeleton), but since he had cancer before his Healing Factor caused the tumors to grow out of control and made him horribly scarred and insane (he thinks he's a character in a comic book)
 * He has also noted that his couldn't bring him back from the silly lengths that Wolverine's has managed - although he can regrow fast enough that his friend Cable would psychically make his head explode for a joke.
 * Well, Deadpool's been shown to recover from being liquefied. When he melted into a puddle, and Cable swallowed him (TO SAVE THEIR LIVES) and then regurgitated him, and Deadpool returned to his solid state almost instantly.
 * Mr Immortal from Marvel's mutant universe has a unique version: he always recovers from fatal injury. It's not shown how he'd cope with just normal grievous bodily harm, although this is rarely an issue—typically, he's facing villains who are more than happy to kill him. And if he was just really wounded, all he'd need to do is commit suicide ...
 * Marvel's The Juggernaut also has an incredible healing factor, once continuing to fight after being reduced to an angry skeleton. This is often not noted because, like the Hulk, he is incredibly difficult to injure in the first place.
 * Paul Kirk, one of The DCU's numerous Manhunters, was given his healing factor by a particularly nasty group of Well Intentioned Extremists, as (apparently) was one of the clones they made of him, also known as Manhunter. In fact, the revival of Manhunter predates the introduction of Wolverine by a year.
 * The vampiric Cassidy from Preacher (Comic Book) could do this, but he had to actually open up someone's vein before he could heal.
 * The 1990s comic book hero Darkhawk doesn't exactly have a healing factor, but he can instantly repair all the damage to his android form by Injuries to Darkhawk's human body couldn't be healed this way, however.
 * Even Spider-Man is shown to have a limited version of this ability, although it seems more that he can just heal faster from injuries that any normal human can recover from, with bruises and sprains often disappearing only a day or two after Spidey is hurt. He certainly isn't Made of Iron to the extent that Wolverine and the Hulk are, however.
 * It's been explained that Spider-Man's body has gained some properties of a spider's exoskeleton. His outside get's the hits, and his insides stay relatively undamaged. That may not be how science works, but the "RADIO-ACTIVE SPIDER BITE" people probably aren't tpp worried about the hard facts.
 * It was initially explained as the relative healing of a spider. And that makes no sense, because humans heal faster than spiders. The exoskeleton remark makes a bit more sense. It would make it harder to injure him, but it would also effect his weight and movement. He would also have to shed it.
 * The Lizardman in the 1990's Spiderman tv episodes—adapted from Curt Connors/the Lizard in the comics—tried to use lizard DNA to regrow his arm, which successfully gained him this power but also made him the unwilling villain of episode one.
 * Venom and Carnage are also close to immortal, where they can heal from anything but continual and ongoing exposure to high-pitched sounds. Or the Sentry.
 * The Savage Dragon can regrow lost limbs, albeit slowly. One villain actually used this against Dragon by breaking every bone in his body, then stuffing him down a smokestack so he healed all wrong. To fix him, another hero had to break his bones again to let him heal correctly.
 * 90s hero Xombi has a Nano Machine based healing factor. It's treated more realistically in that the title character does explicitly need raw organic material to properly heal. In the first issue, his lab assistant is partially devoured when she rests her body against his own while he's healing.
 * Green Arrow II, Connor Hawke, has recently been granted healing powers by the machinations of Dr Sivana in an issue of Green Arrow and Black Canary.
 * Sivana gave him that healing factor using bits of Plastic Man, a character that has survived being turned to stone, shattered, and having the pieces scattered around the ocean floor for over 1,000 years. Yeah, Plastic Man takes this trope to the extreme.
 * Plastic Man doesn't actually heal. He's just Nigh Invulnerable as the result of having total control over his physical structure. It's the same principle that allowed him to change back to his regular shape whenever Circe turned him into an animal.
 * In Immortal Iron Fist, this is one of the explicit abilities of the Cobra Warrior of Peng Lai. Old Cobra once reversed his aging to become a young man again, One Armed Cobra regenerated his long-missing arm, and Fat Cobra managed to grow back both of his legs and repair his severed spinal cord after a fateful encounter with the multi-headed dragon Xiang Yao.
 * Mystique may have a healing factor, or it may just be an extension of her shapeshifting; it's kind of on the fence, and can vary from series to series.
 * Raven of the Teen Titans is able to heal herself by drawing magical energy from the emotions of others. Even with this power, she still falls into comas while healing on a few occasions.
 * Although hurting Superman is pretty hard to begin with, if you manage it, he will recover quickly. He once recovered from a slit throat minutes afterwards. It's unknown if this is a power of his, or just an above-average recovery time that has nothing to do with yellow-sun radiation.
 * It depends on which version you're talking about. Gold and Modern Age Kryptonians were genetically engineered. Yellow solar radiation makes it happen faster. Silver age Kryptonians were normal humans on Krypton. When surrounded by a Red Solar Forcefield, Superman was human but escaping "Shredded every tendon in his legs." Upon escaping "his tendons instantly repair and all the pains of humanity melt away."
 * Doomsday, in The Death of Superman. He's borderline Type I as it takes someone in Superman's weight class to even take him on and then, he can regenerate from anything, including death. The process actually supposedly makes him stronger each time with a new defense adapted to whatever killed him so he can never be killed the same way twice so in theory he's approaching Type I. He's shades of Type 4 also as, unlike some of the others on this list, when he's killed he actually stays dead for days or weeks.
 * Depending on the Writer, The Flash uses his super speed as essentially a form of Healing Factor; he experiences the normal healing a human body is capable of, but at a much faster rate. Kid Flash/Impulse, who shares the same power set, has to deal with one of the downsides when Deathstroke shoots his knee with buck shot: his super speed lets him heal very quickly, but without extracting the buck shot and setting the bone correctly his leg will be essentially useless. Making it worse, his super-metabolism also makes him immune to pain medicine, meaning he had to be awake while his bones were re-broken, set, and the metal was removed.
 * Man-Thing seems to come back from anything as long as he is in proximity to water.
 * Holden Carver of Sleeper has a healing factor as a Required Secondary Power.
 * Space Elf Jedi Master Fay from Star Wars Republic #55 has a healing factor due to her deep connection to the Force. Unfortunately, it fails at a crucial moment because of her giving her Force reseverves to Obi-Wan to help him jump to safety. As a result, she ends up dying from stab wounds inflicted on her by Asajj Ventress.
 * The DCU's Shade is one of these. No matter what you do to him - shoot him full of bullets, blast him to pieces, rip out his heart - he'll always regenerate his injuries. The only way to kill him permanently is to take away his shadow, removing his powers, then deliver a killing blow. In one potential future, he's still going strong after several millennia.
 * Also in the DCU are the Black Lanterns, which can regenerate From a Single Cell and can usually only be destroyed by the combined light of a Green Lantern and any of the other colors.
 * Vandal Savage is another DCU example; he got his immortality from a meteor back during the Cro-Magnon era. He possesses a Healing Factor (as well as other powers) that considerably slow his aging process to the point of it being almost nonexistent.
 * The Five Archons in The Secret History. They can be killed, probably, but they're certainly not easy to kill.

Fan Works

 * Vampires in Luminosity have this. Even if someone tears them apart, unless the flesh is actually kept separate, they will regroup and regenerate. There's only one surefire way to kill one.
 * In Fallout Equestria Pink Eyes, the lead character Puppysmiles is a Canterlot Ghoul. This Puppy can survive outrageous injuries. Her list so far includes being dismembered and devoured by a manticore, taking several antimateriel rifles to the chest, and being cut to ribbons by a Minigun barrage.
 * combines this with The Undead to achieve Immortality in The Tainted Grimoire.

Film

 * Immortals from Highlander have fast healing, recovering from non-fatal injuries just as fast as deadly ones. The only injuries they do not heal from are ones to the neck - this is why they can only be killed by cutting their heads off.
 * Or, according to Highlander the Raven, severing their spine by any other means. They also can not regenerate limbs as seen when a fine young cannibal gets his hand cut off and in future episodes has no hand.
 * John Oldman in The Man From Earth is unsure whether he has one of these (for instance, if you shot him, would the wound heal in front of your eyes?), all he knows is that he doesn't scar.
 * In Godzilla 2000, the genetic origin of this (dubbed "Organizer G-1") is explicitly described as the ultimate source (in combination with its sheer mass) of Godzilla's apparent immunity to attacks.
 * Jeebs from Men in Black has an incredibly effective healing factor as his alien ability. Every scene with Jeebs involves him getting his head shot off, only to have it grow back in the space of seconds. The RPG specified that he had a limited number of several vital organs, including his head. The animated series said his species didn't need to breathe oxygen, but needed it to regenerate. The healing factor didn't apply to all his physiology. After shooting him, K threatens to shoot him again in a place "where it don't grow back."
 * The T-1000 from Terminator 2. It's too bad that a lot of scenes from the end were cut, and are thus not canon. The protagonists did enough damage over the course of the movie, specifically highlighting the freeze-and-shoot moment, that the T-1000 isn't able to completely maintain his form. Moments include grabbing a handrail, and having his fingers stick and assume the color of the warning paint, and while he walks his feet tends to melt.
 * This is also what tips John Conner off that his mom is the T-1000 in disguise.
 * In addition, it has it's limits, as it.
 * In the third X-Men film, Wolverine fights a mutant who can regrow limbs instantly—but is not immune to a Groin Attack.
 * The Hellboy films:
 * Sammael from Hellboy can heal from any non-fatal injury almost instantly.
 * The Clock Punk robots of Hellboy II: The Golden Army can repair themselves after being ripped to pieces.
 * When The Iron Giant gets his arms knocked off by a train, the parts return to him and reattach themselves.
 * The title character of the Tomie series of J-horror films has this ability to the extent that every single individual piece of her that is cut off will eventually become a new Tomie. This is justified, at least in the manga it was based on, by Tomie being radiotrophic, feeding on background radiation in the air & somehow converting it into mass.
 * Brandon Lee's character in The Crow seemed to possess this ability. Right to the point of making a very bad religious joke in between successive on-target shotgun blasts. Too bad the actor wasn't so endowed.
 * Dude, too soon.
 * The Neo-Vipers from G.I. Joe: Rise of the Cobra have one thanks to the nanomites.
 * In The League of Extraordinary Gentlemen, Mina and Dorian actually wonder if they can be killed. They both heal from their wounds in seconds during their fight, prompting Dorian to note, "We'll be at this all day."

Literature

 * Billy "Carnifex" Ray from the Wild Cards series of novels is a slight subversion; he has a Healing Factor that acts as the biological equivalent of "meatball surgery". It will save his life and restore practical functionality, but repeated injuries have left him somewhat misshapen (e.g. a broken nose healing while still bent out of place).
 * Demise has the sort of Healing Factor that just keeps bringing him Back from the Dead.
 * The Mechanic's Healing Factor required him to be in contact with a machine.
 * Stuntman's Healing Factor regrows the damaged tissue violently, leaving him disoriented and very hungry.
 * Jordan the Barbarian from the Xanth books has regeneration as his magical talent, allowing him to recover from anything (anything) up to and including death... so long as his body parts are fairly close to each other. However, after being reunited with himself at the end of a 400-year period of being sliced up and scattered, he did need a lot of food to fully recover.
 * In Diana Wynne Jones's Chronicles of Chrestomanci series, the titular nine-lived enchanters can recover from mortal injuries such as broken neck or 100% burns, but only eight times, and it does indeed make them very hungry.
 * Cormac limbs from the Saga of Darren Shan has the ability to regain lost body parts, when you cut off his head, two smaller heads appear. The guy who decapitated him was suitably freaked out.
 * Wizards in The Dresden Files have a slight healing factor that allows them to live for centuries. Harry notes at one point that, given the abuse he's faced over the years, he'd be facing the kind of constant aches and pains a retired football player does if not for his healing factor. It's no where near Wolverine-strength; in one book, Harry has most of the muscle and flesh burned off of his left hand when a vampiric sorceress realizes his shields don't block heat, and while he's regained some use of the hand four books later, it still looks damn ugly and he wouldn't have been even able to do that much without extremely high level magic from his former teacher (one of the most powerful wizards in the world).
 * The Specials in Scott Westerfeld's Uglies series have Nanomachines in their blood that allow them to heal quickly.
 * Mistwraiths and some Allomancers in the Mistborn books both have rapid healing. Mistwraiths because they can simply alter their body mass into muscle or other kinds of tissue (though they can't create or repair bone), while any Allomancer that can "burn" pewter will gain super-human healing (though we're talking a week or two to recover from a should-be-fatal cut, not regrowing arms in minutes) in addition to the other benefits it provides.
 * The Inquisitors and especially the Lord Ruler have this even moreso. Inquisitors can regenerate from almost any injury, though it takes up a lot of their energy, while the Lord Ruler has been at various points in his Backstory shot, stabbed, decapitated, burned alive, and flayed. He shrugged off all of them in minutes, with no significant harm done.
 * Word of God is the The Lord Ruler wasn't fully decapitated - he only had his neck chopped about three-quarters of the way through. Similarly, when he was burned alive, only the outer layer of skin and muscle was burned. If he had been completely decapitated or burned down to the bone, he would have been killed, but considering how powerful he is as a combatant, this is a lot easier said than done.
 * Feruchemists can save up their health in "goldminds" (feeling horribly sick the whole time) then splurge it all in one burst of incredibly fast regeneration. The Inquisitors' and the Lord Ruler's even-faster healing comes
 * in The Alloy of Law manages the most impressive one. His healing factor is so powerful, he shoots himself in the face with a shotgun just to show off. Repeatedly. Without being even temporarily incapacitated. While possessing no other superhuman powers.
 * It's noted he carries around sticks of dynamite to alleviate his one weakness - that, as he possesses no other superhuman powers, he can be disabled pretty well by tying him up - although you need either well designed nets or several men to do so, because his healing factor still makes him deadly in hand-to-hand. To get around this, he simply takes the dynamite out and blows himself up, destroying the netting in the process. He doesn't really care because his healing factor has been going so long he can't actually feel pain any more.
 * In P.C. Hodgell's Chronicles of the Kencyrath series, the Kencyr peoples have impressive healing abilities, although much of it requires dwar sleep, a hibernation-like mode of deep, restorative sleep which can, for severe injuries, last for weeks. Jame, the protagonist, sleeps for thirteen days after she arrives in Tai-tastigon with severely infected haunt bites (haunts being essentially zombies); her healing astonishes the human healer who tends to her. Kencyr can also regenerate lost teeth, and through dwar sleep can recuperate from punishing speeds on foot, allowing their armies to cover ground at a sustained rate much faster than human armies can attain.
 * Averted, and possibly inverted, in The Belgariad, where the gods have no healing ability whatsoever because they're normally invincible and have no need of it.
 * The  from the Warhammer 40,000 Grey Knights novel Dark Adeptus has one that allows for real-time regeneration of fairly severe damage,  . The Grey Knights themselves, as Super Soldiers, have a better-than-human regeneration, though they still need an apothecary for severe stuff.
 * In Octavia Butler's Fledgling, the protagonist recovers from being caught in a burning building—it's implied that she had severe head injuries and was blind at the start. At the end of the process, she's fine except for the amnesia, but she needs fresh meat as soon as possible, and is too hungry to notice where it comes from.
 * As the Doctor Who Expanded Universe Eighth Doctor Adventures are a bit Bloodier and Gorier than the Doctor Who TV series, it's much more evident that the Doctor has a certain degree of this ability in the novels than it is on TV. The Doctor regrows a tooth at one point. He walks on a severely broken leg, is severely stabbed, gets shot full of buckshot, has one of his hearts ripped out, etc., and always gets better with a minimum of fuss and no medical attention.
 * Tempus from Thieves' World has a healing factor that was given to him by his patron god Vashanka. However, as this is Thieves' World and Vashanka is the  generally nasty Rankan war-god, there's obviously going to be a catch. In this case, Tempus heals from anything that doesn't kill him at about the normal human healing rate. This is particularly crap when
 * In the Parrish Plessis series, one of the abilities granted by The Corruption is enhanced healing. The effects aren't too extreme; the infected can still be killed by mundane means, and still need a while to recover from severe injuries like broken bones. It is, however, quite good at dealing with toxins, which lead some well-intentioned people to start spreading it around as a cure for the pervasive heavy metal poisoning in their slum. Then the others side-effects of infection began to appear...
 * The protagonist of the abominable Baldur's Gate novelisations, Abdel Adrian, gets this in the second book. Due to  his injuries will simply heal after a while, even when bits come off. This mainly serves to counterbalance the fact that, even though he's an awful Canon Sue, he kind of sucks at fighting. Also, it increases the Gorn potential by letting him be sliced up too.
 * Lanik Mueller from A Planet Called Treason comes from a family who achieved a Healing Factor through generations of genetic modifications. It takes a lot to kill a Mueller. (They routinely cut off each other's fingers and pry out eyes in childhood squabbles.) Puberty is kind of spectacular in them: In their teenage years, their healing factor gets somewhat out of control and they constantly grow many redundant body parts. Their body stabilizes once they reach maturity... except for the "radical regeneratives" whose Healing Factor remains out of control permanently. Such poor souls lose all rights and are treated as cattle from which organs are harvested for trade.
 * Halfway through the book, Lanik's body is so gruesomely destroyed that the Healing Factor malfunctions spectacularly and accidentally regenerates his loose innards into a living conjoined twin. When Lanik recovers from feverishness enough to realize what has happened, he cuts off the twin and kills him in panic....
 * Atticus O'Sullivan of the Iron Druid books can regenerate almost any injury ... as long as his bare skin is in contact with soil.
 * Trolls in Poul Anderson's Three Hearts and Three Lions regenerate unless damaged by fire. This is likely the origin of this concept for trollish regeneration that was later adopted by Dungeons and Dragons.
 * Immortals and Marra in The Madness Season can both heal themselves of injuries that would otherwise be fatal, so long as they, respectively, have enough blood or life force to spare.
 * Lucy from Lucy's Blade has this, as does anyone who is possessed by Lilith, which means they can't even get sick. But it isn't that super human - a seriously bad wound could still kill them because there is only so much energy Lilith has and is able to pump through a mortal body without killing her friend.
 * Killing an engineered in Duumvirate is a matter of either inflicting direct brain damage or making them lose enough blood. Their regeneration isn't what makes this difficult, however...
 * Dr. Cherijo Torin of the StarDoc novels is this way, thanks to the interference of Sufficiently Advanced Aliens in the process that created her. She even survives a point-blank gunshot wound to the head, although her memories and thus personality are severely altered by the event.
 * H.P. Lovecraft's Great Old Ones, or at least Cthulhu, have this form of immortality. In Call of Cthulhu Cthulhu gets a boat driven through his skull, turning his head into green paste. It reforms instantly. In writings of one of the later mythos writers, he's also gotten vaporized by a nuclear strike, only to reform himself. According to some writers, they can be killed by another Great Old One (or other godlike entity) while other sources state that they are completely unkillable.
 * Vampires in Women of the Otherworld are like this. Their only special power is incredible healing. At one point, one vampire who had her throat cut is able to walk and talk a few minutes later.
 * one of the Wilds in Trudi Canavan's trilogy "The Age of Five". He gained immortality through his great knowledge of healing magic. This even allowed him to
 * The Animorphs are this. Even though they're normal kids, the Andalite morphing technology they've been given is based on DNA. If they're injured while in morph, all they need to do is demorph to human and their injuries will be gone. Likewise, if they're injured while human, they just need to morph and then demorph to have a perfect DNA-based body again. No injury, no matter how serious, will kill them unless it kills them instantly. As long as they're still alive and conscious after the injury, they can recover. If they miss their two hour time limit in morph, all bets are off.
 * Anyanwu from Octavia Butler's Wild Seed is a shapeshifter with an impressive Healing Factor; she can only be killed by something that would kill her instantly (presumably, decapitation or the like).
 * The Dullahans in Durarara!!, set in the same world as the above example also appear to regenerate their wounds, though it takes longer for them to heal. It's unclear whether it's possible to wound one badly enough to kill them permanently, but this doesn't seem to be the case.
 * Humanity as whole possesses this in Robert Reed's Great Ship universe. Artificial emergency genes and massive amounts of genetic engineering allow the body to recycle wastes and such very efficiently, and it can re-purpose mass to be used for other things - chop off someone's arm, and the emergency genes break down the appendix and some less used muscles to regrow it in a few days or weeks.
 * Corwin, and by extension, the rest of the Amberites and Chaosites in The Chronicles of Amber. As he says, "I heal faster and better than anyone I know." Notably, this isn't instantaneous, but it is still accelerated compared to normal humans, and is considerably better. At one point, Corwin regenerates his eyes that were burned out of his head with branding irons, even recovering the optic nerves. It takes a few months, but he makes a full recovery. He and Benedict speculate that Benedict, who has lost an arm, will regrow it given enough time.
 * The Honorverse has both quick-heal, which simply massively speeds up normal healing, and regeneration therapies, which can regrow limbs and other things within a matter of weeks, though it simply doesn't work on a sizable percentage of people, including the main character.
 * A Certain Magical Index:
 * Motoharu has the Level 0 ability Auto-Rebirth. It's very limited, and can only stop bleeding by reconnecting damaged blood vessels. Being a Level 0 ability, it also doesn't work 100% of the time.
 * If Touma's right hand or arm is severed, it will completely regenerate . This happens even if the severed limb is completely destroyed. However, this worked differently the first time the arm was severed. The arm didn't regenerate on its own, but when reattached by doctors, it healed with unusual speed. Interestingly, neither of the other two characters with a special right hand has this power.
 * Magic Gods have an extremely powerful healing factor. They can recover from a broken neck or an impaled chest instantly.

Live-Action TV

 * The X-Files played with the healing factor's similarity to the rapid cell growth of cancers; a man who could regrow his whole body almost at will showed up in lab reports as having a wide variety of cancers, and he needed to eat tumors to survive.
 * Appears to be the only sort of power ascribed to grim reapers in Dead Like Me, beyond the ability to yoink souls out of bodies. An example George accidentally runs her hand through a paper shredder, losing a finger in the process. she picks it up out of the basket, holds it back in place for a few seconds, then goes and washes the blood off her hands.
 * Claire Bennet from Heroes. Wile E. Coyote has nothing on her. Nothing. Also, . Peter Petrelli has the same power via absorbing it from Claire, and
 * The Season 3 episode, "I Am Become Death", shows Claire.
 * To be fair,
 * The Wraith in Stargate Atlantis.
 * Captain Jack Harkness of Torchwood comes Back from the Dead whenever he encounters lethal damage. When he does, the damage is healed, regardless of whether it was mundanely or supernaturally inflicted.
 * Taken to a disturbing extreme in the series two finale, where he is.
 * Taken to yet another disturbing extreme in the Children of Earth miniseries, where he has.
 * This regenerating thing of his is however not because of a natural, biological healing factor. Poor sod became
 * He loses his healing factor in Miracle Day, and after the Miracle (which stops everyone on Earth from dying, no matter how badly they're injured) there is speculation that he many now be the only person on the planet who can die..
 * Adric from Doctor Who has this ability, thanks to his species' capacity for incredibly rapid adaptation. It only gets mentioned in two of his stories, though.
 * The Info-Text for State of Decay uses this to poke fun at a continuity error regarding a mysteriously disappearing patch and rip in Adric's trousers where he skinned his knee in Full Circle, saying that apparently "Alzarian trousers heal as fast as their owners."
 * In the 2005 episode "The Christmas Invasion", the Doctor is shown to be able to quickly regrow severed limbs for up to 24 hours after regenerating, using leftover regeneration energy.
 * Buffy the Vampire Slayer - Buffy has a lesser healing factor as part of her Slayer powers. She can't regenerate injuries in front of our eyes, but she does recover from serious injury much faster than a normal human (at least if she also gets medical assistance).

Vampires also have this healing factor, though it may not be as strong as Buffy's. Spike was stuck in a wheelchair for several episodes, and Drusilla was heavily weakened by an attack which required a ritual to heal. In some ways it can be stronger than Buffy's, as vampires are clinically dead, they don't have to worry about things like blood loss.

Spike recovered at some point before he actually got out of the wheelchair; in one scene he reveals he'd been faking it for an unspecified amount of time. Angel has been gutted and run through an unspecified number of times, particularly in his spinoff show. Illyria also threw him through two windows several stories off the ground.
 * In The Sarah Connor Chronicles, Robot Girl Cameron's epidermal layer heals unusually quickly, to the point that a gaping, deep wound that had to be stapled closed healed to the point that is just looks like a recently patched-up cut the next day.
 * The Collector: Collectors quickly recover from any wound, with Hellfire spewing out of it in the process. A client also exhibited it(minus the flames) with fatal wounds; Because of the Devil's obligation to clients, they are protected from death for the duration of their deal, one way or another.
 * Revealed as an ability that Pilot's race has in a scary early episode of Farscape.
 * In Highlander, immortals don't get sick and any injury that doesn't involve a missing body part heals in minutes. That is, a severed stump will heal, but limbs don't grow back.
 * While The Flash has long had some degree of faster than normal healing (See above in comic books), the 2014 incarnation of The Flash gives the character a much stronger one, able to heal a broken back in a week.

Myth and Legend

 * The Lernaean Hydra, of Heracles/Hercules fame, was so difficult to kill because for each head the hero would cut off, two would grow in its place. The fact that its blood was also a deadly poison didn't help either. Only when his nephew Iolaos started to cauterize the stumps with his torch could Heracles finally kill the monster; this may be the (or at least one) source for the idea that fire is bad for regenerators.
 * Prometheus had his liver torn out every day, and grown back by the next. Over and over again, for centuries.
 * The Greek gods have this kind of immortality, which includes not aging. According to most writers, they can't die from anything. To add to this, the myths say that Chronos is still alive despite being cut up into tiny pieces and scattered across Eternity. Further, Chronos did the same to HIS father who is also still alive despite that. In fact, Chiron, one of the few GOOD centaurs, ends up needing to have is immortality taken from him somehow since the hydra venom in his body couldn't kill him and just continued giving him horrible, mind-searing pain.

Tabletop RPG

 * In Dungeons & Dragons, the Regeneration ability changes normal damage into subdual damage and the ability to recover so many Hit Points' worth of subdual damage per round. Thus, if you don't use the attack form that does cause normal damage to the foe, they cannot be killed, merely knocked out for a while. There is also Fast Healing, which merely causes the character to heal a certain amount of normal damage per round and thus allows real death to occur much more easily, shutting off the power just as normal healing would be.
 * The ultimate example of this ability is the Tarrasque. Its renegeration ability has no damage type exception, meaning that no matter what you do to the monster it'll come back eventually unless you use a magical Wish to wish it stayed dead.
 * In previous editions, there were particular forms of regeneration that varied from monster to monster. The D&D troll, arguably the most famous example, can quickly regenerate wounds from swords and axes, and by themselves these weapons can't kill them, although they can knock them out temporarily by reducing their hit points to zero. The only thing that can kill them are fire and acid, which also cause damage that can't be regenerated. Whether you blow them up with a fireball, or knock them out with a weapon and then set them on fire or douse them with acid, you need to burn trolls to kill them if you're using standard tactics. If beat into helplessness, they can then be drowned also if there is water nearby (as there often is as they often inhabit swamps). Trolls being vulnerable to fire is likely originally taken from the novel Three Hearts and Three Lions.
 * 4e Lycanthropes (were-creatures) have regeneration instead of damage reduction, it is suppressed by, you guessed it, silver.
 * Regeneration is used to create Puzzle Bosses sometimes in the game; However, it occasionally backfires through really counterintuitive or contradictory responses being required, e.g. the Tendriculos, a Man-Eating Plant, regenerates from fire and axes, and is vulnerable to electrical attacks and blunt weapons. Another man eating plant has a sort of healing factor in that it gains health from being hit by electrical attacks (the Shambling Mound).
 * Healing Factor is the name of a feat in the Eberron campaign setting. It allows shifters to regain health whenever they return to their normal form.
 * In the recent fourth edition, regeneration works more like the previous fast healing ability and does not function at 0 Hit Points or less. On the other hand, 'special' attacks (fire vs. trolls, silver against lycanthropes) generally only suppress it for one turn before it kicks back in.
 * Certain types of Damage Reduction, a defensive ability that reduces the severity of each attack a creature suffers (possibly negating it), are described as wounds closing instantly rather than simply not being as severe as expected.
 * Everything has ridiculously fast healing in 4e. For example, a power called "knee breaker" only lasts a few rounds.
 * In the second edition of the game, a sufficiently high Constitution score (read: godlike) gave you this ability.
 * Werewolves in both Werewolf: The Apocalypse and Werewolf: The Forsaken have an accelerated healing factor. The later game, Werewolf: the Forsaken, actually plays up the cancer element; if a werewolf's wounded with silver, there's a chance they could develop a malignant growth not entirely unlike cancer.
 * One of the fomori powers in Werewolf: The Apocalypse provides this, except that everytime you regrow something, but always with nasty scars and often malignant tumors as well. Being a fomor is completely disgusting, seriously.
 * Vampires in both Vampire: The Masquerade and Vampire: The Requiem can heal about as quickly as Werewolves, but they must expend blood they've ingested to do so, and the strength of their healing factor depends on the damage type. Wounds caused by bashing or gunshots heal faster than wounds from stabbing or slashing weapons. Damage from fire, sunlight or a supernatural source takes even more blood and time to heal.
 * This is the Hat of the Necrons of Warhammer 40,000.
 * Well one of them, their primary Hat is that they are hyper-advanced robots.
 * To a lesser degree this applies to the Orks, who are capable of healing from any non-fatal wound quite quickly, and when you consider how "tuff" they are, a fatal blow is difficult. In fact, standard Imperial procedure is, after a battle with Orks, to go around and cut the heads off their bodies with entrenching shovels to make sure they stay dead. About the only non-fatal thing that they can't regenerate on their own is severed limbs and they can still stitch the lost limb, or even someone else's limb, back onto the stump and have it heal together pretty quickly. They can even reattach severed heads and walk off like nothing happened!
 * With a bit of help from mutation, Tellos of the Soul Drinkers picks up this ability. It gets to the point where he can run into battle naked from the waist up without suffering meaningful damage. It doesn't help with injuries from before he gained this ability - so he can't regrow his hands - but that's not much of a problem when you have chainsaws attached to your wrists..
 * The Carnifex is even tougher. One of them survived Exterminatus. On the planet's surface. When they found it, they had to call in a heavy-duty orbital bombardment to finish it off.
 * Magic: The Gathering has various spells and abilities that allow creatures to regenerate instead of going to the graveyard, wiping out all damage they may have suffered in the process (as well as tapping them and taking them out of combat). These usually require some cost to be paid (usually in mana) and there are forms of destruction that explicitly cannot be regenerated from... -- Creatures also recover from damage that fails to kill them pretty quickly by default, as 'remove all leftover damage from stuff still in play' is one of the automatic events of the last step of each turn. (Players aren't so lucky.)
 * Lunar Exalts in Exalted are stated as being able to recover from terrible injuries at an astounding rate whilst in their warform, if not in battle (they must use separate healing powers for that purpose. They can regenerate lost limbs and internal organs (assuming they aren't dead) at a rate of one such organ or limb per hour, good as new and fully functional.
 * Regeneration in GURPS ranges from slow enough that people would have to hang out with you for a while to notice it all the way to so fast that you heal your total HP every second.
 * Regeneration is a game effect in Warhammer fantasy roleplay. It is common enough to be in the main rulebook rather than the army specific ones and it is cancelled by fire.
 * Warhammer Fantasy Battle featured a hero called Valtan as part of their Storm of Chaos event who, by reason of being probably the avatar of a god, had a healing factor good enough that there was a 5 in 6 chance of him surviving any attack that took his last wound with no ill-effects, hopping back to his feet to fight again. In certain corners he became known as yo-yo Valtan.

Video Games
"Joe: He's a doctor, deals a lot with people in our line of work. You shouldn't need to see him though, Vito, you always seem to heal quick enough. Must be your diet."
 * The Nameless One in Planescape: Torment. In gameplay terms, this results in speedy regeneration of lost hit points. Also, some tasks take full advantage of this ability, requiring that you cut out various body parts and use them for some purpose probably not in the human body's user manual.
 * The healing factor is such that The Nameless One can spontaneously come back from the dead, too - there are a few quests in which 'killing' yourself is a valid solution.
 * Vito of Mafia II can shrug off and recover from bullet wounds that would leave his mobster companions cringing in pain (in cutscenes, at least)


 * In City of Heroes, the "Regeneration" powerset emulates this.
 * With a bit of creative tinkering, it was possible to create a Regen Scrapper that was essentially Nigh Invulnerable to attack from enemies ten levels higher and more... in a game where a four level gap was considered impossible for anything less than a full team. Suffice to say, the developers nerfed this ability no less than four times in a row.

This is also why, in a game where numerous characters are disproportionately powerful in battles of attrition, and hit-run-and-repeat tactics are intentionally left viable, there are still things which take a group to bring down - their intrinsic combat regeneration is just too strong to overcome by anybody who can indefinitely survive their assault.
 * The Wood Golems in the Disgaea series have this as their passive ability, which regenerates 20% of their HP each turn. They can also pass this onto another unit by becoming a Magichange weapon for them.
 * White Mages in Final Fantasy XI have a version of this, when at level 25, they get Auto-Regen, which constantly restores 1 HP every 3 seconds. If they don't get hit after getting hurt and stand still for(At most) an hour, they can go from near-dead to full HP, so this trope does count.

Most of the Final Fantasy games have a similar Regen spell, most of which restore a set percentage of HP each turn, while the one in Final Fantasy VII restored HP constantly. If combined with a Haste effect, attacks that hit for less than 500 or so HP wouldn't even register on the status bar. "Marisa: Shall we do it again? Maybe you really are invincible. Alice: Invincible, maybe, but she seems worn out. Mokou: I've already reached my limit. I'd better stop before I'm unable to move tomorrow. Alice: So, muscular pain only, eh?"
 * Devil May Cry - The potent-or-not Healing Factors of Dante and Vergil constitute one of the series' more annoying Cutscene Power to the Max moments.
 * Kyouya from Diabolo, despite his terminal illness, claims to heal in his sleep (and considering after a night's rest some scratches on his face disappeared, this may not have been a bluff).
 * Mega Man X gets it in the third game when he gets either the enhanced helmet or the Golden Armor.
 * Team Fortress 2 has the Medic class. Although a class designed to heal others, the Medic can also heal from any damage back to full health, which is good when you consider that he can't turn his medigun on himself. If the Medic goes a certain amount of time without getting hurt again, he regenerates faster. In total, it takes less than half a minute to regenerate to full health, even from the last hitpoint. Equipping the Blutsauger reduces his regeneration speed, while equipping the Crusader's Crossbow and Amputator will increase his regeneration speed instead.
 * Trolls in the Warcraft universe have a healing factor known as Troll Regeneration. They can regenerate limbs unless fire, magic is used or if they angered their loa gods. In-game, this translates to regaining lost HP points without the aid of healers or potions. (in World of Warcraft everyone regains HP in this manner, but Trolls do it faster) and are the only ones tha can do it while in combat.
 * It's also very, very weak and the butt of several jokes about its insignificance. In a game where characters have tens of thousands of Hit Points: "I'm regenerating 5 health per second and there's nothing you can do about it!"
 * The Warrior class actually has several abilities and talents that perform exactly this; while other classes can heal with magic, warriors (and druids that use the same rage mechanic) are the only class that can heal grievous wounds with anger. Unlike the troll racial ability, they can return from the brink of death to greater than half health in mere seconds if left unmolested.
 * Blizzard actually forgot trolls had this ability (along with many other things) in the trailer for the subpar instance Zul'aman. For those confused, in the trailer, a troll cuts off his arm with a regular broken spear and it doesn't grow back.
 * This was handwaved later as Troll's needing to "be in balance with the loa (nature spirits) of their tribe" in order to heal, with the amount of favor a troll has been given by the loa proportional to how fast they can heal, meaning a troll that has fallen out of balance/favor with the loa (such as Zul'Jin appearently) will be unable to heal missing limbs, or if they really piss them off, unable to heal from even a paper cut.
 * In Warcraft 3, you have to research the ability if you want your Trolls to regenerate faster. Even then, it has about no effect during a battle, though it does help to save on Healing Salves after the battle.
 * The final boss in Serious Sam: The First Encounter, Ugh-Zan the Third, is a towering behemoth who is nearly impossible to kill thanks to his regeneration abilities. To kill him, a player will have to wear him down first with his own weaponry before activating an enormous death ray to finish him off before he can trigger his healing ability.
 * Albedo, one of the antagonists of Xenosaga, has this ability to the level that makes him immortal. This is in fact why he is
 * The main character in Shadow of the Colossus doesn't have much in his favor, but it helps that he can take a crushing blow from a Godzilla-sized hulking monstrosity, get pounded into the dust, and as long as he's still alive he'll shake it off in a minute or two.
 * In Mass Effect, this rapid healing is one of the abilities of the Soldier class, as well as the Krogan Battlemaster class.
 * It's a racial ability for both vorcha and krogan in the Mass Effect universe—the former because of their unique cell structures, the latter due to very resilient physiologies that include secondary and sometimes even tertiary organ systems (for a start, they have fully redundent nervous systems). In Mass Effect 2, in fact, they will heal from brink of death to full health in seconds unless you hit them with an Incinerate or Warp power, or shoot them with Incendiary (and possibly Warp) Ammo.
 * The Touhou Project series features Kaguya Houraisan and Fujiwara no Mokou whose healing factors are derived from the Hourai Elixir, the Elixir of Immortality. Theirs is a Type IV immortality; they can resurrect from total bodily destruction, feeling every little thing along the way and, as suspected, getting used to it. The only way the protagonists can fight Mokou in an otherwise safe duel in the Extra stage is by attacking her for lethal durations and repeatedly killing her until she is too tired.


 * Also, Remilia Scarlet has been stated to be able to regenerate indefinitely so long as at least something remains of her being, such as a piece of bat flesh. Though we never actually see her regenerate from an apparent death, we are treated firsthand to her ability to infinitely spawn bats from herself, ALL of which are fair game for her Healing Factor. Essentially, unless you make extremely sure there's no trace of her left at all, she's nigh unkillable.
 * Ten Desires brings us Yoshika Miyako, a Jiangshi with the "ability to eat anything and everything", who uses this ability in-game to restore her health by absorbing spirits. This can make her first and third spellcards, the ones that make use of this ability, annoying to capture, as for the first you have to refrain from shooting down the bullet-shooting enemies Yoshika produces, and for the third card, you must weave through her bullets and slip past lasers to get close to the boss when she summons a bunch of blue spirits, so you can collect them before she does.
 * A recent First-Person Shooter (as well as other shooters) trend has been to apply this trope to the main character. It doesn't matter how many bullets have pierced your body in total over the course of the adventure: As long as you can find some cover to hide behind for a few seconds before this particular batch of bullets kill you, you're fit for fight again.
 * Nathan Drake from Uncharted Drakes Fortune is thus able to run around punching gun-wielding mercenaries to death, as long as he can dart in and out of cover.
 * Developers handwaved this particular aspect of Drake as his health not actually representing his well being, but rather his (incredible) luck. The idea here is that Nate is effectively pushing his luck the longer he stands in the line of fire, and there is a point at which fate gives up on him and lets him die.
 * Similarly, Marcus Fenix of Gears of War runs around without a helmet because this trope allows him to.
 * In Dragon Quest III, several of the bosses have healing factors, sometimes as much as 100 HP per round. It's especially nasty because this happens behind the scenes, and the player is given no indication of it.
 * Shirou has this in Fate/stay night, spurring his famous "people (should) die when they're killed" line when he chooses to abandon it.
 * All of the Servants have absurd levels of regeneration as well. The speed of regeneration depends upon the Heroic Spirit summoned as well as the amount of mana available, but even lost limbs will eventually regenerate. Though not quickly. To fatally wound a Servant, you have to destroy or damage the two points that serve as their core; their head or their heart.
 * One of the player character's augmentations in Deus Ex is Regeneration, this requires power to use.
 * Deus Ex Human Revolution features a healing augmentation that can restore you to full health in a few minutes, balanced by the fact it takes a few seconds to kick in and your character is more fragile.
 * In Prototype, Mercer can heal over time when not under attack. It's faster to eat people though.
 * Several Pokémon abilities and moves do this, such as Recover or Rain Dish (when it's raining). The "Leftovers" item gives a Regen-like effect, while the Poison Heal ability grants it when the Pokemon is "suffering" from poison. Introduced as an ability in its own right in Generation V, where Pokémon regenerate a small amount of health when recalled.
 * Many Pokédex entries give certain pokémon this ability. This doesn't affect the game.
 * Dungeon of Doom let you accelerate healing by slipping on a regeneration ring. Just make sure it isn't one of those unremovable negative regeneration rings...
 * Expect Xenomorphs in any Alien vs. Predator game to have regen abilities. It can be accelerated with a quick headbite. It ties into the mythos; Xeno's are adapted to be the perfect survivors. In the (unfortunately extremely rare) RTS, human Radiological Ammo stops it.
 * Elena from Street Fighter III has a super move that allows her to regenerate up to one-third of her health.
 * Fallout 3 features a very slow healing factor in the form of the 'solar powered' perk. As you would expect you need to be in direct sunlight for it to work. Another perk 'rad regeneration' heal limb damage but not overall health, you also have to have advanced radiation sickness for it to work. Other fallout game have the a 'healing rate' which works in the standard way. There is also a 'microregen' rate (natural healing) in the games code (not the manual)that was 'inherited' from Oblivion, this restores health very very slowly.
 * STALKER's main character has a slow healing factor, assuming you don't bleed to death first...
 * The mechanic is closer to Gradual Regeneration, with some Heal Thyself and Hyperactive Metabolism thrown in if the player needs health more quickly. However, the right combination of high-level artifacts can bring this much closer to a super-human Healing Factor level, just beware the possible side effects...
 * In the BioShock (series) series, the Little Sisters personify this trope; because of the huge amounts of Applied Phlebotinum coursing through their veins, they can reconstruct their bodies instantly. In fact, they heal so fast that they frolic around with no suits at the bottom of the ocean. They heal so fast that their skeletal structure reconstructs itself 'before they explode from pressure.'
 * However, Bioshock 2 reveals that it's not all that it's cracked up to be. According to one Audio Diary, when a Little Sister fell off some railings, her leg bones regenerated in odd angles, forcing doctors to break her legs until it healed right. The diary ends with the doctor saying that although they may heal, he can confirm that they feel pain.
 * Two games have a water based healing factor, BioShock (series) 2 has the Fountain of Youth gene tonic and Giants: Citizen Kabuto has it as Delphi's natural sea reaper trait.
 * Metroid - Ridley devours his enemies to repair wounds. Aside from cloning/cybernetics, no one really knows how he reappeared after being tossed down a kilometers long shaft or being completely disintegrated.
 * Vamp in the Metal Gear series has the ability to recover from apparently-fatal injuries (including multiple stabbings and headshots), after the Patriots used him as a guinea-pig to test an experimental strain of nanomachines.
 * Riviera: The Promised Land has Ledah, who regenerates HP every turn, as a temporary playable character during the prologue, making it seems impossible for you to get a game over even though the protagonist keeps dying again and again.
 * In Valkyria Chronicles, Alicia has a potential called "Mysterious Body." Apparently, ever since she was a little girl, her wounds were always very quick to heal. This comes from her power as a Valkyria, but is never explained from a practical standpoint. However, despite her gunshot wounds healing rapidly, she needs Welkin's knowlegde of herbs for a sprained ankle.
 * Rogue Squadron: Ships equipped with an astromech droid will gradually regain health as the droid makes repairs. However, if your droid is destroyed you lose this ability.
 * An incredibly disgusting version is used by in Dead Space who   while flailing and oozing. Where it gets the extra tissue required is unknown.
 * StarCraft's Zerg have a healing factor, which shows up in-game as their units (and buildings) being the only ones to regenerate Hit Points over time. Roaches in particular can go from near-death to full within seconds when burrowed.
 * In Ghost Trick,
 * Fittingly, shra in The Reconstruction have very high rates of bodily regeneration, though not to the extent of most Healing Factors. This is deconstructed with Skint (who does have a very potent Healing Factor), who got stabbed in the back with a large sword...and his body healed the wound, with the sword still in. To make things worse, the sword was lodged through his heart, making it impossible to take out without killing him. It also means he can never take off his armour, which must make sleeping pretty difficult, too.
 * Qualstio's final passive skill, Physidrawing, gives him high regeneration rates as well (in gameplay terms); it is not as strong as the bodily regeneration of the shra, but regenerates all his gauges quickly. Plus, being intrinsic regeneration, it's still stackable with regeneration buffs.
 * Many boesses in Super Robot Wars do not only have HP regeneration, but they also completely heal themelves when you defeat or successfully reduce their HP to certain amounts. Some endgame bosses tend to go so far as doing this three times.
 * The Stranger of Oddworld: Stranger's Wrath can literally shake the pain away.
 * One of the effects of the Mantle skill in Fire Emblem : Radiant Dawn is regenerating an amount of HP equal to Luck at the beginning of each turn. All the enemies with this skill have maxed Luck... The Imbue and Renewal skills also allow the holder to regain HP at the beginning of their turn, but contrary to Mantle they are not specific to one unit since the game mechanics allow skills to be traded between units. The Black Knight also has the Imbue skills, which cannot be removed from him.
 * The Lost Odyssey characters have something more like this kind of immortality in actual gameplay; they can be injured and knocked out in battle, but automatically revive after a couple of turns.
 * In Chaos Rings and Chaos Rings Omega, the winning Battle Couple is granted immortality that regenerates any injury short of vital organ removal and special telomeres that halt the aging process. It comes with a 10,000 year time limit though.

Web Comics

 * Schlock, from Schlock Mercenary, as an amorphous life form, can regenerate from any amount of mass remaining, but as his memories are distributed throughout his body, he loses his mind if he takes enough damage. His eyes are actually separate lifeforms, that grow on trees on his homeworld. Uusually for this trope he needs to regenerate from what's left of his own mass. If enough of that is lost, he explicitly needs a large outside source of organic material.

Additionally, medical technology of the twenty-third century can regrow your body from the head down in less time than it takes you to naturally heal a paper cut.
 * Laz'r'us grade nanites appear to be able to provide this, as witnessed on the two occasions they're called on (for Kevin and General Xinchub).
 * In Sluggy Freelance, Oasis has a healing factor according to this strip. Whether this is the cause of her numerous Back from the Dead moments is unclear.


 * It's suggested by several characters within the strip (including Torg, Riff, and Oasis herself) that she's actually a ghost that possesses people to such a degree that they take her form clear down to her crazy hair making this more Grand Theft Me although the author hasn't cleared it up for us yet.
 * K'Z'K also has an amazing healing ability coupled with immortality. At one point Bun-Bun ran him through a meat grinder and turned him into burgers. He was up and rampaging again by the next strip.
 * Every member of 4U City has a 'snapshot' taken of themselves clear down the the firing of every neuron in the brain that can be used to regenerate them with nanomachines. Too much damage causes them to revert to the state they were in when their snapshot was taken which happens frequently to some (Riff's wife) and less for others (Executives like Rammer).
 * One of the Super Soldier implants in SSDD has this effect
 * The protagonist in ATXS, Raocow's webcomic is so incredibly stupid that she has the ability to forget and thus, heal every and all wounds.
 * Damien from El Goonish Shive is expressly stated to have this. Grace and her "brothers" as a shapeshifters presumably has this as well and by extension all Seyunolu and Uryuom have this to a certain extent.
 * Wayward Sons: All Ulympeans and Tytans got this along with their Personality Powers. Beheading is the only way to kill them now.
 * In Elijah and Azuu, it's common for both angels and demons to recover from grievous injuries, but one storyline firmly established that Azuu could easily regrow his arm after having it hacked off by a sword that specifically halts a demon's healing factor. His mom was injured by the same sword in an earlier story arc, and she had to consume several souls in order to recover.
 * In Jack those who  are apparently this, unfortunately they usually don't realize this. And it's implied to not be a good thing
 * Webcomic artist Tiffany Ross loves this one so much, two unrelated series have variations of it:
 * The Cyantian Chronicles has it as one of the traits of genetic elites including Alpha and his son, Syrys, Shean Tibal and his bad-boy son, Rama, as well as several cubs (at this point only shown with Rama's son, Vin). Also it only works if the subject is moving, as elites were originally intended as pit fighters.
 * Alien Dice gives us Lexx, who has been injected with repair nanites by the ADC so he can play their game and make the corporation wealthy.
 * of Wapsi Square was revealed to have this power.

Web Original

 * Global Guardians PBEM Universe - This was a very common power.
 * The all-time champion was probably Splatterman, so-called because he seemed to end up as chunky salsa every time he ended up in combat. Being aware of how quickly he healed, Splatterman would often put himself in position to have this happen, because he knew it wouldn't really slow him down. Leap off the top of a building? Sure. Jump through a wood-chipper? Yep. Swallow the live hand-grenade? You bet. And like a Timex, he took a licking and kept on ticking.
 * The villainous Nematode not only regrew parts that were cut off of him, but the parts would regrow into whole beings as well. Cut off an arm, and suddenly fight two Nematodes.
 * This is so common in the Whateley Universe that there is a Regen scale describing how fast any mutant recovers from injury. Carmilla once was decapitated: her head grew back while the assailant stared in shock. Tennyo had her entire arm blasted off by a supervillain: she spun around and had completely regrown her arm by the time she got to him, intent on massive retaliation. Other characters have this to a lesser degree, including Generator and Peril.
 * Rick Point Blank: The plot revolves around a serum that heals wounds when it's poured on them and grants a Healing Factor that would make Wolverine jealous when injected.
 * In The Salvation War, the demons and angels have extremely fast regeneration, to the point that they can regenerate lost limbs completely and can recover from any other injury given enough time, provided they don't immediately bleed out. This is deconstructed later on in the story's discussion thread, after : the rapid regeneration rate, coupled with   results in uncontrolled cancer growth in the survivors. The deceased humans are also capable of healing rapidly.
 * Veldron of Super Stories can regenerate when very close to death, causing many to assume that he has this power all the time. He doesn't.
 * Trinton Chronicles has Xiion who heals at a highly rapid rate which he can do at will for a faster rate of healing or subconciously for a slower but faster-then-normal rate.
 * In Cracked.com:
 * Discussed in 7 Video Game Healing Methods Least Likely to Actually Work
 * A healing factor is portrayed as undesirable in 6 Awesome Superpowers (That Would Suck in Real Life) because the intense pain would lead to post-traumatic stress disorder.

Western Animation

 * Starscream gets this in Transformers Animated from an Allspark fragment in his head.
 * Which is based on how G1 Starscream was Ret Conned into having one to explain how he came Back from the Dead.
 * But that was only his spark (soul) which was immortal, he didn't have a body, regenerating or otherwise. Which lead to him floating around like a ghost for quite some time until he could scam himself a new shell (or steal someone else's).
 * Transmetal 2s in Transformers: Beast Wars have the ability to heal mild to moderate damage near-instantaneously using energy from their spark. Rampage also has one, as he was created by an experiment to duplicate Starscream's spark.
 * Godmasters in Transformers Super God Masterforce have this as one of their defining features.
 * Megatron in Transformers Cybertron can regenerate damaged parts of his body much more easily than ordinary self-repair systems thanks to the Armor of Unicron. Stealing a Dark God's power has its perks.
 * A common Fanon in Kim Possible is that Shego has this as well. Probably inspired by the fact that her hands can generate a plasma-like fire hot enough to melt steel and never seems to have as much as a scratch after being kicked around by Kim.
 * Canon if you go by the movie where she survives a life threatening blow at the end without more then some messed up hair.
 * Gargoyles have a form of accelerated healing attached to their stone sleep. Spending a day in stone sleep cures them of any wounds, infections or toxins in or on the body. However, if a body part is amputated, it's gone for good. This only applies to their hibernation. Until the sun rises, they're as badly affected by an injury as any other creature. Demona and MacBeth appear to have this, too,
 * SpongeBob SquarePants, being a sponge and all, can grow back severed parts of his body with no problem. He was surprised when he found out others couldn't do it as well.
 * Presumably true of Meltman, since without this he'd be kind of a one-suicidal-trick pony; to even know he has "the power to melt," he must have melted at least once. Though given the nature of the show, it's hard to say.
 * Bushroots Healing Factor is seldom seen, but he completely recovers from being squashed in his first episode and later from being shreddered into small pieces.
 * Killface of Frisky Dingo has a rather handy healing factor. Metal pipe through the lung? Nah, tend to Simon's scraped arm. Rocket through the chest, and a gaping hole from the explosion? Fixed with a little bedrest. Though his Healing Factor was unable to heal his eyes after he was blinded by AntAgony.

Real Life

 * The axolotl is a neotenous amphibian that can regenerate limbs and organs that were damaged or lost. Although it doesn't give it Immortality, it does make it live much longer. It's used as a model in biomedicine.
 * Salamanders are perhaps the most complex animals capable of regenerating limbs in adulthood.
 * There are some species of starfish that not only grow new limbs, but the detached limb can grow a new starfish!
 * Sponges can be put through a fine strainer and they will eventually recoalesce.
 * Flatworms can regenerate bits, including heads, although it's possible to mess with this in ways that result in two-headed flatworms.
 * Some round and segmented worms also can do that, but with the two-tailed and two-headed mistakes as well. It generally depends on the location and extent of the injury.
 * Most leafy plants are able to regenerate from practically any damage, as long as they can still acquire nutrients and the materials needed to synthesise sugars (in other words, their roots and leaves still need to be at least partially functional).
 * Not even necessarily the roots—many plants can be propagated from cuttings. In fact for a large number of domestic fruit trees, grafting a piece of an existing tree onto an existing rootstock is the only way that they are reproduced.
 * Moreover, using special nutrition, leaf plants may be regrown from a single cell.
 * Nope, this troper has seen willows regrowing from piles of wood-chips.
 * There is anecdotal evidence that toddlers can regenerate fingertips that have been severed for whatever reason (not the entire finger, just the top 1/8 inch or so).
 * Supposedly, a man was able to regrow a fingertip that was cut off by applying a special powder, given to him by a researcher, to the open wound. There was a report on The BBC a while back.
 * That sounds like dehydrated Extra Cellular matrix, its a sort of universal animal cell growth medium, by applying dehydrated stuff to the wound it re-hydrates and triggers the growth of the surrounding tissue.
 * The liver in humans is said to regrow from just a third of its normally functioning tissue. This is why living-donor liver transplants are possible (although hardly easy): the donor can lose 55-70% of his or her liver and expect to have it back to near 100% functioning within six weeks, and it will be fully up to normal size and structure within two to three months.
 * Blood platelets. When flesh is cut, leading to bleeding, blood platelets are life-savers. They cause blood clots (better known as scabs) along the cut, stopping the release of blood until other body functions can fix up the blood flow. This makes them sort of a pre-Healing Factor Healing Factor.