Taerel Setting: The kin'toni (vampires) have a healing factor due to stem cells, with most minor wounds closing within a few hours. They are able to regrow lost limbs within months. They are able to heal gunshot wounds within days.
- SCP Foundation. Generally speaking, any SCP item tagged "self-repairing" will have this to some degree.
- SCP-290 ("The Picasso Machine"). While a person is undergoing bodily reconfiguration inside SCP-290, it grants them rapid healing as part of the process to repair the harm it causes them.
- SCP-378 ("Brainworm"). When SCP-378 occupies a human being's brain, the host gains the ability to almost instantly regenerate physical damage. In one case a host tore off his own arm and attacked using it as a weapon. When he pressed it against his shoulder it re-attached immediately.
- SCP-415 ("The Harvested Man"). SCP-415 heals from damage at an accelerated rate and is able to re-grow lost internal organs.
- SCP-428 ("The Crowd"). Damage to SCP-428’s "crowd" heals at a faster than normal rate. For example, a bullet hole will close up within a few days.
- SCP-446 ("Human Mannequin"). According to document Document 446-1-A, any wounds SCP-446 receives will heal within 5-10 minutes with no scarring.
- SCP-466 ("Mobile Veins"). SCP-466 is noted as being able to heal any damage to itself at an accelerated rate.
- SCP-628 ("Flute Copse"). When cut, the trees heal at a tremendously accelerated rate. A tree cut completely through can heal within a day.
- One of the defining characteristics of SCP-682. The only long-term solution for containing it is to keep it in a vat of concentrated hydrochloric acid, and even then it still sometimes manages to temporarily escape.
- SCP-1160 ("Effective Containment"). SCP-1160 can quickly and completely regenerate injuries and lost body parts.
- SCP-1262 ("Seed of Destruction"). SCP-1262 can rapidly regenerate damage to itself, making it difficult to eradicate.
- SCP-1368 ("Aegides"). SCP-1368 can absorb dust and use it to rebuild its structure, allowing it to heal almost all types of damage except fire.
- SCP-1495 ("Karmic Musth"). SCP-1495 elephants heal from injuries at an accelerated rate.
- SCP-1557 ("Giraffe Hell"). SCP-1557-A are giraffe souls condemned to SCP-1557. Any damage inflicted on SCP-1557-A is quickly healed by unknown means.
- SCP-1627 ("Mushroom Wars"). A human being infected by SCP-1627 fungus can become an example of SCP-1627-A. They will be completely healed of all damage, including tissue damage, bacterial and viral infections, and cancer. Any person that touches an SCP-1627-A will temporarily gain the same benefits, but will suffer Rapid Aging and die over the next two weeks.
- SCP-2102 ("Got Shoggoth?"). As a result of the experiment that created it, SCP-2102 can heal its wounds a quadrillion times as fast as normal. Unfortunately the process doesn't stop when the healing is completed, and the subject's body grows out of control.
- SCP-2260 ("Traveler's Journal"). When a human being is exploring a remote area using SCP-2260, their body will heal from injury at ten times the normal rate.
- SCP-2922 ("Notes From the Under"). When a human being implanted with SCP-2922 dies, they go to an afterlife that the Foundation calls Corbenic. The body they have there regenerates all physical damage it takes in seconds.
- SCP-4820 ("The Custom Of The Sea") is a sailor who gained the power to rapidly regenerate wounds after getting shipwrecked on a desert island. Unfortunately, there were no plants or animals on the island, and he still needed to eat. It didn't take him long to think of a solution.
- 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 subconsciously for a slower but faster-then-normal rate.
- In We Are Our Avatars, Yasmin can heal incredibly quickly, to the point that she's incredibly apathetic toward pain. There's also Ozzy (A.K.A. Gina), Snake, and various other Gods/Characters who have this ability.
- Whateley Universe:
- This is so common 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.
- Note that regeneration in the WU can end up as Blessed with Suck in a number of ways, and the potential for problems rises with the strength of the healing (though the specific form of regeneration has an impact as well):
- While Wildman's body survives the No-Holds-Barred Beatdown Kodiak gave him in their arena match, the result of Wyatt putting his fist through Tony's skull was that his brain regenerated as a blank slate. Wyatt's guilt over this is a significant factor in some of his later actions, but the isolation it caused due to other students being afraid of him was also the lever Freya used to turn Kodiak into her personal enforcer.
- Different regenerators react differently to drugs and alcohol: some aren't affected, or are only affected the first time they are exposed to it; some burn through it very fast, getting the full impact, withdrawal, and recovery in a matter of hours or minutes; and some others, such as Circuit Breaker, have unpredictable results completely different from normal reactions.
- For regen 3 and higher, their blood is a hazardous material, and blood transfusions from such regenerators often end up turning the recipient into a clone of the donor, often with Death of Personality as a side effect.
- The worst potential side effect of regeneration is 'regen cancer', which mostly affects those in the regen 3 to 5 range: once a tumor has started, death is inevitable, swift, and gruesome, as their body becomes a mass of out-of-control cells that eventually explodes into chunks.
- Worm:
- Othala has the power to grant regeneration to other people.
- Then, of course, there's Crawler who can regenerate any injury in seconds - even having half his brain teleported into a parallel dimension - and then develops a permanent resistance to whatever hurt him in the first place.
- The Endbringers have this as well. It's not fast enough to heal wounds in the same fight they got them in, but it's powerful enough for them to regrow their entire bodies from their cores if necessary.
- Scion has this turned up to eleven. Any wound he suffers heals so rapidly that it's hard to tell he was ever hurt at all. He rarely needs to use his healing, though, as he's so Nigh Invulnerable that there's little on the planet that could possibly harm him even slightly.