Immortality isn't exactly a superpower you can easily prove to the skeptic. Sure, you can say that you're Really 700 Years Old, but who's to say that they'll believe you? And, while you may have that Healing Factor, you need to be injured for that to work. It's not like you can have your arm sliced open on demand just to prove that you—
Wait a sec, you can.
Self-Mutilation Demonstration is the favorite method of Immortals for proving to others their powers. The method is simple: grab a sharp object, slash open your arm (or any other body part), and let your Healing Factor kick in and amaze your guest. In other words, you take Good Thing You Can Heal to its logical extreme, deliberately injuring yourself for the sole purpose of proving you have a Healing Factor. Let's hope you also have the superpower not to feel pain.
Sometimes, the empowered individual will ask someone to just Hit Me, Dammit!. This is either a stylistic variant of the same thing, or a character is using to mock Mooks by revealing that this is one thing they have in common with Superman, particularly to justify hitting them back to much greater effect.
Not to be confused with Self-Harm.
Compare Macho Masochism, which is more about harming yourself just to demonstrate how tough you are, without the regeneration powers to back it up. Contrast Impostor Exposing Test, which may use a similar action to prove that the character isn't anything special. See also Immortal Life Is Cheap, which can occasionally be used by other characters to nonchalantly display another's immortality by hurting them severely.
- This was a Once an Episode trick for Yuta in Mermaid Saga. It even got so common that his girlfriend eventually started predicting when the "I'm really five hundred years old..." speech was about to occur and started inconspicuously searching for the nearest pointy object to use.
- Happens occasionally in the Baccano! series.
- Firo uses his ability to "bleed in reverse" as a party trick. Hey, it's better than card tricks.
- Huey does it frequently too, though he tends to use more violent methods like setting himself on fire or ripping open his jugular. It's a good way of testing the witnessing "specimen"'s mental fortitude.
- Melvi performs this discreetly to Firo by biting through his lip as he introduces himself.
- Fullmetal Alchemist:
- Greed proves he has the Healing Factor by asking a flunky to smash his head in with a giant, pointy mallet. It almost happens again later, but he waves down the flunky (already readying his hammer) because they don't have that kind of time.
- Lust also rips open her own chest to show Mustang and Havoc her Philosopher's Stone.
- Phoenix: Masato does this after Phoenix the grants him immortality, first slicing his skin open with a knife, then shooting himself.
- In D.Gray-Man, there's a scene where Road Kamelot tears her own face off using Allen's anti-Akuma weapon so she can show off her Healing Factor.
- In the Queen Camillia arc of Descendants of Darkness, Hisoka stabs himself in the hand to prove to Tsubaki that he is indeed a Shinigami, and to try to get her to believe him when he says that Muraki is not the angelic hero she thinks he is.
- Ciel does this in differing ways between the manga and the visual novel of Tsukihime. In the manga she stabs herself through her eye to the squicking of Akiha, and in the VN she slits her own throat to the amazement of Shiki.
- Kira Sakuya from Angel Sanctuary repeatedly injures his arm to prove to his host body's father that he is actually a soul that has taken over his real son's dying body.
- Angel Beats! right off the bat in a variety. Otonashi asks Angel(Kanade) to prove him he's dead. She stabs him in the heart. He survives! ....Or not. Now he knows he's dead for sure.
- After draining Joseph Joestar's blood, Dio Brando of JoJo's Bizarre Adventure decides it'd be fun to demonstrate to Jotaro just how invincible he now is by casually tearing at his own face and ramming his finger through his own skull while he taunts him. With his newfound power, the damage heals instantaneously.
- Mobile Suit Crossbone Gundam has Tobia doing this to Sharidon after she attempts to get him to join her Newtype supremacist movement. Tobia responds by slugging her to the ground, then cutting his own arm with a knife and splashing the blood on the ground in front of her before running off. Sharidon gets the message: "The blood is the same; there's no real difference between Newtypes and ordinary humans." It doesn't turn her away from her beliefs, but it does convince her that Tobia is never going to join her.
- A version that shows both Healing Factor and Kryptonite Factor in Assassination Classroom: Koro-sensei shoots one of his tentacles with the anti-sensei BB bullets in front of the entire class to show that the bullets really do work and he indeed dodged all the bullets. The tentacle grows back a few seconds later.
- In later chapters, he shoots a few of his tentacles to show that his Super Speed is reduced with every tentacle lost.
- A member of Youngblood once cut off his own arm when asked what powers he had.
- In an issue of The Sandman, an Indian fakir, seeking an audience with a powerful sultan, impresses the palace guards by severing his own hand at the wrist (a wound which, naturally, doesn't bleed) and then reattaching the hand with no loss of function afterwards. Subverted slightly in that although he's immensely powerful, the fakir isn't immortal: he does possess a fruit which grants immortality to whoever eats it, but he refuses to use the fruit for himself.
- There's a vampire comic by the Finnish artist Petri Hiltunen which starts with the vampire holding a pistol while facing his human guest. The human thinks he's going to get shot, but the vampire actually just wanted to prove to his skeptical visitor that he's a vampire — he shoots himself in the head, and the wound disappears in a couple of seconds. To clarify, the man assumes that the vampire is just a crazy person, and is trying to intimidate him with a gun into agreeing that he is what he says he is.
- Batman: "Contagion" features a man who thinks he can do this after walking through a plague zone and being unharmed. Turns out being immune to a disease does not translate into being immune from other harm.
- In Seven Soldiers of Victory: Klarion, Submissionary Judah smashes his fists against a book with iron pages in order to demonstrate his willingness to spill his own blood for his people.
- In The Mask (the original Dark Horse version), Walter is a Made of Iron hulking bruiser with a masochistic streak, who regularly hurts himself just for fun or to gross out other people. On one occasion, he takes a switchblade and starts cutting the side of his face casually as his employer tries to tell him what he wants Walter to do, and looks quite startled when his employer snaps and tells him to knock it off. On another occasion, he pounds nails into his hand to form a smiley face, then clenches his palm so the blood runs out around the nails and walks away, smiling to himself.
- Midori in Ninja Tail demonstrates her Healing Factor abilities by having Deidara blow off her hand with one of his bombs and simply regenerating from it when asked why she was partnered with him.
- Jennifer's Body. Jennifer burns her own tongue with a cigarette lighter, and slashes herself in front of Needy when she decides to share her 'secret' with her.
- Terminator 2: Judgment Day has John Connor order the T-800 to show Dyson he really is a robot. The T-800 peels off the skin and muscle of his arm, only to look at the exposed endoskeleton dispassionately. Dyson is understandably horrified by this, so it takes a few seconds for it to sink in...and then he's horrified for a different reason. His wife, who wouldn't have recognized the significance of the arm, meanwhile was probably wondering what the hell was going on.
- In Men in Black, K shoots Jeebs in the face mostly to unveil The Masquerade to J.
Jeebs: You insensitive prick! Do you have any idea how much that stings?
- In The Medallion, Jackie Chan's character is made immortal by the eponymous artifact, and tries to prove this to his partner by asking said partner to first shoot (the partner refuses, saying there'd be a ton of paperwork if he discharged his weapon) and then stab him. After he refuses to do that, Jackie stabs himself. On seeing he's unharmed, the partner then takes the knife and keeps stabbing him in awe of the regeneration.
- In Highlander, when Connor MacLeod decides to reveal his secret to the love interest, he clears up any lingering doubts about his immortality by stabbing himself in the chest with a dagger.
- Freddy Krueger does this a few times in the A Nightmare on Elm Street series, mostly just to horrify his victims. In the first film, for example, he says "Watch this!" before cutting his own fingers off, causing a strange green liquid to squirt from them. Later, he answer's Nancy's "What are you?" by cutting into his own chest, revealing more green pus and what looks like maggots under his skin. In the second movie, he emphasizes his "You've got the body, I've got the brain" line by peeling back the skin on his own skull. In the sixth, he cuts off his fingers (again) while counting the ways people have tried and failed to put him down for good.
- In the first Wishmaster movie the Djinn blows his brains out at the heroine's command, from which he automatically recovers, thereby demonstrating two things: he must do whatever she says, and he is not to be gotten rid of that easily. He does concede that it hurt like hell.
- In Species, Sil casually cuts off her finger with cutters and lets it grow back, utterly terrifying a woman she had kidnapped.
- It's not done to show immortality, so it might not count, but in one Animorphs, a recently freed Hork-Bajir is suspected of being controlled by a Yeerk (parasitic alien brain-living slug). His response is to ram his arm blades into his skull and pull his head apart to show his own Yeerk-free brain. Those observing, Tobias, Ax, Marco, and Jake, are all approriately horrified and disgusted. Tobias, the narrator of that particular book, points out "it's not like it didn't hurt him, either. I could see the pain on his face." He has a Healing Factor, but it doesn't make it any less awesome.
- In the Women of the Otherworld novel Stolen, Cassandra is trying to convince Elena (a werewolf) that vampires are real, despite standing in broad daylight and wearing perfect makeup — which she would have needed a reflection to apply. So she takes a ballpoint pen and stabs her own hand. The wound doesn't bleed and heals almost instantly.
- In Interview with the Vampire Louis remembers when learning about his new attributes, he jammed a dagger in his arm, and before he could pull it out, the body had healed itself around the dagger.
- In the Popol Vuh (Maya mythology) the hero twins use this power to defeat the evil Lords of Xibalba. Xbalanque cut Hunahpu apart and offered him as a sacrifice, and Hunapu rose from the dead. The Lords demanded that the Hero Twins try it on them. The twins did half of the trick...
- In Tuck Everlasting Tuck, after realizing he's immortal, to test it out he shoots himself through the heart. It passes right through him like water.
- In Thief of Time, a yeti invites Lobsang and Lu-Tze to chop off his head in order to demonstrate the yetis' Save Scumming abilities.
- Miles Hundredlives from The Alloy of Law apparently once shot himself in the head with a shotgun to show off his insane Healing Factor.
- The title character of the Mediochre Q Seth Series, while technically not immortal and also susceptible to pain, demonstrates his Healing Factor to some villains in the first book to prove that they will probably not win in a fight and should just back down. He opts to blow off his own finger and watch it regrow.
- In The Danilov Quintet by Jasper Kent, this trope is inverted, when the protagonist sees a vampire's fingers get cut off and they don't grow back. (It turns out vampires can, with willpower, stave off regeneration. At at the time, several years before the events of the book, it wasn't known that he was a vampire.) Played straight when in the second book said vampire cuts of the same two fingers and lets them grow back, in order to jog the protagonist's memory. The protagonist's son, who at the time is unaware of the existence of vampires, is understandably freaked out.
- Mr. Croup and Mr. Vandemar do this in Neverwhere via a knife to Vandemar's hand.
"Oh, Mister Vandemar," [Mr. Croup] said, enjoying the sound of the words, as he enjoyed the sound of all words, "if you cut us, do we not bleed?"
Mr. Vandemar pondered this for a moment, in the dark. Then he said, with perfect accuracy, "No."
- The ghost kids in the Goosebumps book Ghost Camp do this repeatedly.
- Not done to show immortality, but in The Color of Distance Juna cuts her arm open with a scalpel to show the doctors her healing powers.
- In Dead West, this is used by Gervas, demonstrating that Niall is out of control. He cuts himself with a piece of a broken teacup, and it almost instantly heals. Inverted with that Gervas himself doesn't have a Healing Factor, but the Porcelain Doctor's Power Incontinence worsened. Our narrator points out that it still hurt like hell, but he managed to convince Niall to try and rein in his new powers by training on him.
- Various Undying do this in the Horseclans books. On one occasion, Mara does it to Milo, after seeing him survive what appeared to be a fatal wound, just to make sure he really is. When that fatal wound heals, she cuts her own wrist to show him that she's Undying too.
- Eden Green opens with the title character's best friend punching her hands bloody on rusty sheet metal to demonstrate her new healing factor.
- Inverted in Citadel. Jason Grim's power is to drain the life from living things; each life makes him stronger, and can be expended to instantly heal his wounds. He goes into one class combat tournament hopped up on nearly a million fruit-fly lives, making him basically unstoppable. The tournament ends with him pitted against his friend Jenny Awesome, whose power doesn't work on him. Before the fight starts, he pulls out a lighter and holds his finger in the flame until his regeneration consumes all the fly lives, then shows her his blistered finger to prove that he's fighting her fairly with neither of them powered up.
- Eli in Vicious tests out his newfound healing abilities by repeatedly slitting his wrists, though he does this to satisfy his own curiosity rather than to prove a point to anyone else.
- Claire (who used to be in the trope image) has been known to do this quite a few times. To prove to herself that she really can heal, Claire cuts off her own toe and watches her foot grow a new one to replace it. It was more to test how well she can heal, not that that makes it any less crazy.
- Adam, upon finding out about his Healing Factor, starts to mutilate himself just to watch his body heal within seconds.
- In Buffy the Vampire Slayer, when the mayor becomes invulnerable in human form, he has a demon-slaying knight slice his head from the top to his neck. The two side reattach almost immediately. He later catches a letter-opener hurled at him by Angel with his palm, leading to this exchange:
Angel: Can't be killed, but you don't like germs?
Wilkins: Uck, eew, awful things, unsanitary.
- Highlander: The Series:
- An episode has Duncan doing this to an Immortal that has lost his memory.
- In another episode it's shown in flashback how he convinced Tessa of his immortality. He shot himself.
- Methos does it in another episode, cutting open his palm to demonstrate his immortality to a Watcher he knew.
- In Blood Ties, Henry demonstrates his vampiric nature to Vicki by shoving a knife through his hand.
- Daisy did this once in an episode of Dead Like Me.
- Inverted in First Wave, when Foster is captured by people claiming to be government agents who know the truth about the Gua. To prove he is really human, the agent in charge lets Foster stab him in the hand, as aliens have a Healing Factor. The hand doesn't heal, convincing Foster. Later, it is revealed that all this was an elaborate alien ploy. In fact, it was difficult for them to create an arm that wouldn't heal.
- In The Gates, a werewolf slices his arm to reassure his succubus girlfriend that she doesn't need to worry about accidentally hurting him.
- In Eureka, recently-fired scientist Carl Carlson sticks a knife through his hand to prove to his old boss that he has, in fact, finally created a process for spontaneous cellular regeneration.
- The Collector: One of the Devil's clients doesn't remember or believe that she made a deal when the deadline approaches, so Morgan convinced her by cutting himself, showing his hellfire-powered healing.
- Subverted in The 4400, when Kevin Burkhoff stabs himself in the hand (which heals) to prove that he has created a serum that can give people abilities.
Diana: (astonished) You've successfully manifested a 4400 ability.
Burkhoff: It's getting there. It doesn't always work.
Diana: ...you just stabbed yourself in the hand.
Burkhoff: Yeah. I was a little worried about that.
- A variation in Jekyll. During his Establishing Character Moment, an unfortunate teenager is threatening Mr Hyde with a knife, and saying he'll hurt him if he comes any closer. Hyde says "Ya think!?" and slowly stubs out his cigarette on his own palm. This is not to demonstrate healing abilities ( Hyde doesn't yet realize the full extent of his powers), and is simply to show how un-intimidated he is, but it is still a demonstration involving self-mutilation.
- Played with in an episode of Smallville where Clark demonstrates his Nigh-Invulnerability by taking a pistol and firing it several times into his hand. He then drops the expended rounds and shows the other guy his sooty but otherwise completely unharmed hand.
- On an Alternate Universe episode of Misfits, Nathan proves to the world that he is immortal by shooting himself in the head and resurrecting on live TV.
- On the pilot episode of American Horror Story: Coven, Queenie shows off her human Voodoo Doll abilities (she can injure herself and cause it to appear on other people without harming her) by stabbing herself with a fork in order to injure Madison.
- In Season 6 of Dexter, this was how Travis proved to Professor Gellar that the two of them were chosen by God to bring about the apocalypse by recreating scenes from the Book of Revelations. Travis stabbed Gellar with a holy sword, and Gellar's skepticism vanished as he watched his own wound heal miraculously... or at least that's how Travis saw it. Gellar actually died from the stab, as you'd expect, and the "Gellar" that has been calling the shots throughout much of the season is actually Travis's hallucination.
- Inverted in an episode of Lois & Clark. After Superman tries to stop a world-ending asteroid by slamming into it, he succeeds, but the blast sends him crashing down, resulting in Laser-Guided Amnesia. As he's slowly recovering, his parents are shocked to find out that he doesn't know that he is Superman. Naturally, Clark is a bit scared when his father picks up a baseball bat and prepares to hit him, while claiming that it's going to hurt him more than Clark. Naturally, the bat breaks into splinters, convincing the amnesiac Clark.
- A variation in an episode of Painkiller Jane. The team is hunting a Neuro, who is capable of generating illusions in other people's minds, which he uses to kill them. As part of a ploy to stop him, the team pretends to hit him with something that they claim reverses his powers on himself. To demonstrate that he's in a nightmare, Jane shoots her own hand and then shows it to him, as the gaping wound rapidly closes. The Neuro is convinced, although Jane has to really keep from wincing from the pain.
- Burn Notice liked to frequently remind viewers that while physical torture simply doesn't work, mind games, on the other hand, are sometimes risky but can work wonders. One of their interrogations involved Sam convincing the guy he was talking to that Sam was a crazy sadist by having Sam pretend to get all worked up about how he was going to use the giant knife in his hand on the guy being interrogated, and then "crazy" Sam sliced open his own finger and starting dripping the blood all over the guy's face while continuing to babble on. As you can probably imagine, this completely freaked the guy out.
Michael: [narrating] There's a saying in interrogation: "Violence perceived is violence achieved." You don't want someone screaming. You want him asking questions, asking "What is he doing with that knife?" Asking, "lf he'll do that to himself, what will he do to me?" Mostly you want him asking, "How do I make this stop?"
- My Hero has George shoving a wooden spoon through his ears at one point to show Janet's parents that he's (to quote him) "completely impervious to pain and injury". A second later, he realizes they've fainted.
- iZombie: When protagonist Liv finally confronts her cop partner Clive and reveals to him zombies exists, he is understandably skeptical about it. Being unable to convince him without proof, she demonstrates her zombie nature by stabbing herself with a kitchen knife, which triggers her Game Face and allows her to heal the injury.
- In Babylon 5, Narn who swear a blood oath against someone customarily send the target of their wrath a video of them making the oath and then slicing themselves on the head.
- Downplayed in an episode of Charmed. Piper goes a little back in time and is trying to recruit her past self to help her. To prove that she's who she's saying, and not some doppleganger demon, she pinches Past!Piper really hard and then shows the bruise that appears on herself.
- The Nameless One in Planescape: Torment does this rather often. You can even do it to convince someone not to commit suicide. Or you can have him break his neck just to scare people. You can also make good money by letting a jaded Sense Freak experience a sensation of consequence-free murder. And then, later on, you discover that every time you did that during the game and died, you essentially killed an innocent consequence-free. You Bastard.
- Albedo from Xenosaga on at least two occasions shows off his immortality through self-decapitation. The first time, he's not aware that his brothers can't do it, so their shocked reactions convince Albedo that he's a monster.
- A variation of this is stated to have happened to Lord Recluse in City of Heroes. Though not to prove it to others, but rather to himself. No one ever exactly gave him a manual on what becoming a demi-god fully entailed, so he proceeds to burn, cut, bash and crush himself in various ways, with medical care standing by just in case, to see just how immortal he actually is. Says he had been meaning to test if he could survive a bullet to the head but never was willing to go through with it. He did however find out several times over that Immortality Hurts!
- A variation of this trope is used in Ever17. In the Jellyfish Gondola, Tsugumi shows that she has a disease that makes her immortal by killing her pet hamster Chami, which is also infected by the disease. After seeing Chami's shocking sudden death, Takeshi sees an even more shocking sight as the hamster just regenerates so quickly that it looks like he never died after only a minute.
- Ciel in Tsukihime does this to prove her Immortality to Shiki, slitting her own throat in front of him.
- Jurinjo of Emergency Exit makes a large cut in his arm to prove his healing powers to Jason so that he can fix Karl's face. He still feels the pain though.
- Jin of Wapsi Square uses a variation to show that she is indestructible here.
- Steve Weatherby in Captain Stupendous does this by stabbing himself in the throat
- Retroactively occurs in Homestuck. Gamzee, at one point, parries Nepeta's claw attack and decides to scrape it against his face. Later, we learnt that Gamzee is functionally immortal, not because he reached God Tier as was initially believed, but because of literal Joker Immunity.
- Dragon Ball Multiverse: Done by Cell and Gast Carcolh in one of the minicomics.
- In Lee's first appearance in S.S.D.D he stabs himself with a fork to demonstrate what their new implants are capable of to Julian and Tessa.
- Kenny tries this in South Park by shooting himself in the head in front of a group of his friends, but because of his immortality's built-in Weirdness Censor, everyone's forgotten about it by the next day.
Kenny: This time, try and fucking remember! (blows his own brains out)
Stan: Kenny, no!
- In Star vs. the Forces of Evil, a young Queen Moon confronts Big Bad Toffee and his army of lizards. To show her that they are indestructible, one lizard bites off another's arm, which then regenerates. The second lizard then uses his new arm to high-five his old arm.
- In Mighty Max, the psychotic, Nigh Invulnerable barbarian Spike has a face impaled with multiple branches due to being kicked off of his feet and landing face first in a pile of firewood. He promptly emerged from the pile mocking the idea that this could hurt him, then grabbed one branch and rammed it up his left nostril until it wedged there to prove his point.