Illustration of common Achilles heels. By Olly Moss◊ Examples included
Any seemingly Nigh Invulnerable
character will inevitably have some key weakness that can and will be exploited.
This is especially likely if the main character is a Super Hero
; otherwise they could walk over criminals and other villains and flatten any chance of conflict or personal peril. Aliens and monsters that are Immune to Bullets
will usually have a fairly mundane
Achilles Heel that only surfaces/is discovered when things look the bleakest.
Other versions and variations of the Achilles Heel include:
open/close all folders
Anime and Manga
- Played With for the homunculi in Fullmetal Alchemist. Their immortality is fueled by the Philosopher's Stones in their bodies; Mustang tore Lust's out of her body attempting a one-shot kill, only for her to form a new body from the Stone. Turns out their only weakness is being killed a few dozen times (or the destruction of the Stone itself), with the exact number of "kills" required being dependent on the number of human souls remaining in the Stone.
- Pride has one in the form of pure darkness: since he uses shadow-manipulation powers, he's powerless in total darkness because you need light to cast a shadow.
- Alphonse is bound to his armor by his blood seal, and should that be destroyed, he's a goner.
- Wrath's Ultimate Eye turns him into the equivalent of a Perfect Play A.I.: he can predict his opponents' moves with perfect accuracy and therefore wins almost every fight he's in effortlessly. Even an Ultimate Eye cannot dodge something it cannot see coming.
- Played straight for the homunculi in the first anime, where they are immortal, but can be killed if one gets anywhere near the remains of the human body they were created from. Wrath averts this because his remains were used as the raw materials in the attempt to resurrect him.
- The Zentraedi and Protodeviln of Macross and Macross 7 are both weakened by music - the Zentraedi because they haven't been exposed to "culture" for so long, and the Protodeviln because Basara possesses the Anima Spiritua.
- Any character in Get Backers have fantastical abilities but with very heavy handicaps, more often than not forcing the characters to pull near-fatal trump card moves. The best example is one character of the main duo, Mido Ban, who can subject people to dreams with his Jagan (Evil Eye) for exactly one minute in reality, but indefinitely in the dream itself, making it an ultimate twink move. The catch? He can only use it once on a person and three times total a day. Needless to say, a lot of antagonists find ways to avoid this or force him to use his Jagan needlessly until he's helpless.
- Death Note's Shinigami, being grim reapers, are immortal with two notable exceptions. First, a Shinigami's lifespan is extended by writing names in a Death Note: if a Shinigami forgets to write names, they will run out of time and die. Second is the fact that a Shinigami who intentionally uses their Death Note to protect a human - extending someone's lifespan rather than cutting it short - will die instantly. There are also a number of rules they have to follow while in the human world if they don't want to get on the bad side of the Shinigami King. On a personal level, Ryuk is addicted to apples, and goes through some awkward withdrawal syndromes if he goes for too long without eating any. That said, Ryuk's withdrawal can't kill him, nor can starvation, as he doesn't really need to eat.
- In Science Ninja Team Gatchaman, the team's main vehicle, The God Phoenix, has a rather poorly thought out weakness in that all the team's sub-vehicles have to be docked for the God Phoenix's weapons systems to work. While that kind of weakness would make sense to create the plane's Fiery Phoenix effect since it's an exotic weapon system, to have it affect the regular weapons seems too much. Even worse, Galactor learns about this weakness and the visual clues for it and wastes no time to take advantage of it.
- Another Achilles Heel turned out to be their uniforms. Each piece of their clothes - shirt, pants, and shoes - turn into their uniforms. Lose any part of it and you can't transform, as Jun finds out.
- Although Immune to Bullets, the cyborg assassins of Gunslinger Girl are as vulnerable as any little girl when they are not focused. Furthermore, shooting them in the eyes should be enough to kill them.
- Many times on Saint Seiya, more than one character suffers from this. Shiryu's main means of attacking leaves his heart wide open to attacks for a fraction of a second, something a few people notice over the course of the story. Krishna likewise was only defeated when Shiryu struck his hidden "Star Points", and the Pope of Sanctuary's astral projection attacks left his body wide open to attack.
- The Big Bad of Digimon Adventure 02's only weakness was the Power of Dreams.
- a human artist gains the power to make his art come to life, and starts creating some of the most horrible creatures imaginable as an army to obliterate his enemies. However, once Inuyasha destroys the artist's inkwell — which turns out to be a magic inkwell — he's down and out.
- Inuyasha himself: On the night of a new moon, he becomes fully human and loses all of his demon powers.
- Subverted in Legend of Lemnear. The Big Bad transforms himself into a 50 foot demon cyclops, and the male hero: The warrior of Bronze declares "You may be tough, but I know your weak spot! Your demon eye!" Then through a crazy set of acrobatics, lands on the demons face to plunge a sword into its eye. Only to have his sword shatter on contact.
- Goku of Dragon Ball survives a bullet and an axe to the head (relatively) unharmed, but if you grab his tail, he'll pass out. Eventually he trains himself to not be unaffected by it. It even works when he's transformed into a giant ape. He also has a tendency of losing strength if he feels hungry, which results in his defeat in his first battle with Yamcha as well as his fight with Jackie Chun.
- Goku and Piccolo themselves exploit this weakness in the battle with Raditz. After that attempt failed, Goku didn't bother going for the weakness again, because he remembered that Saiyans could also manually detach the tail from the body. Attempted against Nappa and Vegeta, although Piccolo finds out rather brutally that the Elites aren't stupid enough to not train that weakness.
- Though debatably non-canon, the fourth DBZ movie revealed that Namekians were sensitive to a certain sound frequency. In this case, it's the sound of whistling. Piccolo flips out when Gohan whistles, but when Big Bad Lord Slug has everyone on the ropes, he ends up ripping off his own ears as he instructs Gohan to start whistling to stop Slug.
- Makoto Shishio from Rurouni Kenshin is a very powerful swordsman, but can't fight for more than 15 minutes straight. If he does, he will overheat to death.And by overheat, we mean burst into flames.
- Nagi Springfield of Mahou Sensei Negima! is described as invincible with no weaknesses. Except for the fact that he's an idiot who needs a cheatsheet to remember spells. He also has trouble pronouncing latin.
- Alternatively, his commerade Eishun is a more serious character who for his strong focus on his training means a lack of human contact, and therefore a difficulty with women. This seems a common trait in Shinmeiryuu swordsman if Setsuna is any indication. Tsukuyomi takes this weakness too far in the other direction.
- One Piece
- All Devil Fruit users have the common fatal weakness of becoming completely immobile and useless in deep water. Other fruits have more specific weaknesses; for example, Luffy's Gum Gum fruit makes him immune to blunt force, and can only be damaged by being slashed or pierced. On the other side of the coin, Buggy the Clown's fruit makes him immune to being cut, so his weakness is blunt force.
- The Logia Fruits, easily the most powerful of all the Devil Fruits, all seem to have a single weakness that negates their great power or their perfect defense. For example; Sir Crocodile, eater of the Sand Sand fruit, becomes solid when wet. God Enel, eater of the Rumble Rumble fruit, which gives him lighting powers strong enough to destroy the entirety of Skypeia, is made completely helpless when pitted against Luffy, who is made of rubber and doesn't conduct electricity (until he finds ways to attack Luffy indirectly). Logia Fruit users can also be somewhat physically harmed when up against someone with a powerful Haki, though if a Logia user has Haki of his own he can counter that attempt to bypass his intangibility (as seen when Whitebeard uses a Haki-imbued attack against Admiral Aokiji).
- Franky is a powerful cyborg with superhuman defenses. Problem is, he did all of his enhancements himself, meaning that since he couldn't reach behind him to do anything in back, he's vulnerable to attacks from behind. Some of his moves therefore involve fighting with his back on the ground so that his weak point is harder to reach.
- The Yato of Gintama have immense physical strength, but are sensitive to the sun and carry around umbrellas (which double as guns, shields (bullet-proof?), and are very durable, used something like swords) to protect themselves during the day. On one occasion a character died from being exposed to the sun only briefly, after years of being underground.
- Zanpaku-tou all have some kind of a weak point. Hanatarou's can take the wounds it's healed and turn into an attack powerful enough to kill a Gillian, but afterwards it's a useless three-inch-long scalpel. Consider most enemies in Bleach have a horrible attack radius far, far greater than three inches, this makes him useless in combat. Komamura's bankai can take down most enemies with just one hit, but any damage inflicted upon it also appears on Komamura, so if the enemy survived that hit and was able to retaliate... ouch. Even Aizen's got one - if you touch his sword before he starts the illusion, you can see through them. Also, while his illusions effect all 5 senses, you have to see him release his shikai once before you can be caught in them. Thus, the blind are immune.
- Ukitake is prevented from getting involved in battle by his Incurable Cough of Death. One wonders what he'd be like in good health, because he's fought Yamamoto and Starrk as it is. Fittingly, his zanpakuto's ability is Energy Absorption.
- Quincies have no resistance to Hollows. While Shinigami and even normal humans can survive Hollow attacks if they aren't mortally wounded, Hollows are basically soul-destroying poison to Quincies. This is the main reason Quincies hunted down Hollows so relentlessly. This is bad news for the Vandenreich members who stole bankais when Urahara's medicine temporarily turns the original owners of the bankais into Hollowfied Shinigami.
- In Voltron, it turns out the the right knee where Black Lion and Blue Lion connect is the titular mecha's weak point. The enemy constantly bombards it when they find out about it before they're able to pull away and finish the fight before they lose the leg. However, in the end, they fix THAT weak point and put in another weak point! What the hell?!
- Many villains in Yaiba has this. For example, Bat-Man's weakness to sunlight, the Moon Bunnies' ears and Silver's eye.
- In Pokémon Special, Yellow's Virdian-blessed powers include healing, telepathy, minor telekinesis, and Super Empowering. All this sounds like it would make her an invincible Pokemon trainer, but while her powers do make up for her sub-par battling skills, using them too much runs the risk of her being forced into a deep sleep that cannot be externally disrupted. At one point she gets taunted into using her powers vainly as to get tired out faster.
- The Gundam Double Zeta, the title mecha of Mobile Suit Gundam ZZ, is a powerhouse Mobile Suit armed with one of the strongest beam cannons made by that point. However, said beam cannon was such an energy hog that it would easily run itself out of power if continuously used.
- Power consumption is a big problem in the Mobile Suit Gundam SEED universe thanks to the N-Jammers preventing nuclear energy from being used. Many suits along the way have attempted to devise ways to extend Mobile Suit usage time, such as better versions of the Phase Shift armor and beam weapons that draw from external batteries. The Freedom and Justice are Game Breakers because they have N-Jammer Cancellers that allow them to use nuclear reactors, giving them effectively unlimited operation time. Likewise for Providence, the Big Bad's mobile suit. In Gundam SEED Destiny, N-Jammer Cancellers have been banned by treaty (since they also make it possible for nuclear warheads to be used), so yet another attempt to extend battery life is introduced: a technology that remotely beams energy from the mothership to the mobile suit for a quick recharge without needing to return to the hanger. And inevitably, the treaty banning nuclear power gets violated by all sides in the end.
- This is also the problem concerning the GN Drive Tau in Mobile Suit Gundam 00. As the GN Drive Tau is a mass produced, but incomplete, version of the Celestial Being's normal GN Drives, it's missing a critical component to allow constant energy creation, thus it only has a limited amount when it's powered up and when it runs out, the suit's dead in the water. When a way is found to replicate the standard GN Drives' Trans-Am mode, it allows for a considerable boost in output but also exacerbates the existing weakness of the GN Drive Tau.
- In Great Mazinger, the title unit had a blind spot caused by its Scramble Dash flight pack, allowing enemies to sneak up and capture it. It was later fixed.
- It was also used for Mazinkaiser in Super Robot Wars Alpha Gaiden, with Mazinkaiser's Kaiser Scrander creating a blind spot. The Scrander was removed in Super Robot Wars Alpha 2 to fix this.
- Many magical girls tend to have their Transformation Trinket be their Achilles Heel due to the fact that they need it to transform and, thus, be useful. Many bad guys don't seem to actively go for these items in battle, but a few times they have had lead to a Mid-Season Upgrade, Sailor Moon being a good example as Usagi had one brooch destroyed and a second damaged and needed those upgrades to get her powered up again, as well as temporarily losing access to them at times.
- Attack on Titan has the Titan's vulnerable points as the base of their necks. Harm a Titan anywhere else and they'll just regenerate within minutes, but slice the base of the neck and they die instantly. Why this is the case has not been revealed.
- For titan shifters, it's because the human controlling it is located there, but eventually they revealed why it's the same case for normal titans as well: Normal titans are also titan shifters, just unable to turn back or control their actions, and with their human bodies all but gone (though there's still enough left that removing it kills the titan.)
- Perhaps the most well-known Achilles Heel is Superman's weakness to kryptonite. He's also perfectly susceptible to magical and (sometimes) telepathic attacks. It's also generally accepted that Superman would lose all of his powers while exposed to red solar radiation, since the yellow sun is the source of his power though writers waffle about whether red sunlight instantly depowers him or if he gets gradually weaker as he uses up his stores of yellow solar energy.
- The unstoppable Juggernaut from X-Men is highly susceptible to a mental attack. His costume includes a magic helmet that blocks telepathy, meaning that the bulk of most any fight against him is a desperate struggle to remove the helmet and then a telepath effortlessly dispatching him once that's accomplished.
- Martian Manhunter (and indeed his species) was, then wasn't, deathly afraid of fire, which did, then didn't, and now does again melt him into a puddle.
- The Ultimate Marvel version of Iron Man can't touch anything with his bare skin, even dust, without causing himself excruciating pain—hence the suit. He wore a special body paint that numbed him to a normal level. It also gave him a normal color since the events of his birth made him blue in addition to neural tissue extending throughout his body, the reason for his pain.
- Ultimate Professor X has one weakness... Stairs.
- Traditionally, Green Lanterns have had trouble with the color yellow—except the first of them, whose power came from a different source, and was instead vulnerable to wood. Parodied by the parallel-universe "Green Guardsman" in an episode of the Justice League TV series, whose ring was powerless against aluminum.
- The alien symbiotes, from the Marvel Universe, that created such creatures as black-suit Spider-Man, Venom, Carnage, and Toxin, are vulnerable to "sonics"—essentially, extremely loud or high-frequency noises. Extreme heat is also a notably unpleasant weakness of theirs. There's one time when Venom has been defeated by a lit zippo.
- Conversely, Vemon is Spider-Man's Achilles Heel. Since the Venom symbiote spend a good bit of time bonded to Spidey as his black costume, not only does it know all about the Spider-Sense (something that routinely saves Spidey's life by giving him a heads-up on an incoming sneak attack), it's also immune to detection by it, an immunity that extends to any host the symbiote is bonded to.
- Inverted with the supervillain Doomsday. If you kill him, he comes back, immune to what killed him last time (so, if you tossed him into space, he'd come back able to survive sudden changes in pressure; if you did it again, he wouldn't need to breathe the next time; and if you did it a third time, he might—eventually—freeze, or burn up, and come back immune to that).
- The brilliant, amoral Thanos from the Marvel Universe has a particularly strange weakness: self-defeatism. As Adam Warlock points out in a Breaking Speech in The Infinity Gauntlet crossover, he subconsciously knows he doesn't deserve victory, and thus arranges his defeat without realizing it. The Vision lampshaded it in a dialogue with She-Hulk, explaining that Thanos himself helped the Avengers to defeat him in previous battles.
- Rising Stars features a character completely immune to physical damage. However, he still needs to breathe, and is killed by someone sneaking up behind him and throwing a plastic bag over his head. More generally, in the third story arc, it is discovered that the resistance to damage that, by this point, all specials have, does not guard against radiation. Thus, a special who has spent the last 10 years stealing and hiding nuclear weapons gets radiation sickness, and any special can be temporarily weakened by an electromagnetic pulse.
- The Gladiator, one of Marvel's many Superman expys, is exactly as powerful as he thinks he is, so he can be defeated by denting his confidence. The typical method is for a character to use trickery to make Gladiator think they did a No Sell, then clobber him when his disbelief saps his strength.
- Norman Osborn, the current Big Bad of the Marvel Universe, has one rather serious Achilles Heel: he's a nutcase. As Osborn he's a twisted and brilliant Magnificent Bastard — and a sociopath. As the Goblin he's so batshit crazy he makes his Osborn side look well adjusted. As a result, it doesn't take much effort to get a Villainous Breakdown out of him. At one point due to some "nudging" by imprisoned psychics, just being reminded of Spider-Man lead to Osborn pacing around in his office naked and ranting. And this is still saner than his Goblin persona.
- General Zod's associate Ursa has all the regular Kryptonian powers and weaknesses, but her eyes can't stand bright light. Knocking off her protective goggles will briefly stun her as she clutches her eyes in pain.
- The Eradicator (or at least when he reappeared after Superman's death) was like that, too - he couldn't take Superman's body and ended up forging a new one with the room around him. It wasn't perfect and he couldn't take in light properly, hence his shades. It's because of this that his battle with Steel turned in Steel's favor - he knocked off his shades fighting back.
- Originally Spawn had his necroplasm suit which allows him to do anything, but with a countdown of energy which, when it hits 0, drags him to hell (thought once they stopped displaying the number the energy was at, became more of an Informed Flaw). He's also vulnerable to heavenly weapons in general.
- Man-Thing was Nigh Invulnerable so long as he remained moist.
- In Aeon Entelechy Evangelion due to mobility reasons the joints in the armor (normal or subdermal) are less protected, and therefore exploited.
- In Winter War, Yumichika's shikai power is given the weakness that if he tries to use it against someone with a sufficiently great reiatsu- say, a high-ranking Espada- rather than killing them, he is overwhelmed with their power and effectively self-Brainwashed and Crazy.
- John in With Strings Attached has to eat all the time; if he doesn't, he fades pretty fast. He's also vulnerable to shrill sounds and was completely put out of action when the Hunter's BFS started screaming.
- Genesect in Plasma's Folly appears to be invulnerable to any type of attack, but instantly "dies" if the drive powering its cannon is removed.
- In the Blood Bond, Blood Omen Series, the Unshaper would have been completely invulnerable if it hadn't insisted on using avatars to give destroying the Earth that personal touch.
- The trope's name is outright mentioned by Hobbes in Calvin & Hobbes: The Series when fighting Socrates' dark side - he's not as in touch with his feline roots as Hobbes is, and ends up taken out by a single, well-timed pounce.
- In With This Ring, the Self-Insert has absolutely no ability to resist magic, meaning spells that others would shrug off a crippling to him. Chaos magic is even worse, as it can ignore his shields.
Films — Animated
- In the Disney film Hercules, Phil makes a reference to his old student Achilles and complains about "that furshlugginer heel". He even goes to Achilles's statue, flicks the heel which cause the entire statue to crumble.
- The Omnidroid in The Incredibles could only be harmed by its own weapons.
Films — Live-Action
- The mother of all Achilles Heels is the exhaust port on the Death Star in Star Wars, through which an invincible planet-destroying space station can explode into an enormous fireball because of a couple torpedoes from a small one-man fighter spacecraft hit its reactor and caused a chain-reaction explosion.
- In the EU, it's made the clear the Emperor was pissed there was such a massive flaw, and the designer repeatedly killed, brought back to life, and then killed again. The second Death Star attempted to avoid this, by instead having lots of little exhaust ports all of which would be to small to shoot into. Luckily, the heroes still had an Achilles Heel to exploit because Death Star II was only about 70% complete when they attacked, which included holes allowing them to fly right up inside the main reactor and torpedo it.
- Possibly the silliest Achilles Heel in film history was in Signs, where the powerful aliens who had been wreaking havoc turned out to have a fatal weakness to ... water. They shouldn't have invaded a planet two-thirds covered in water without protective suits.
- Independence Day. Not only is the alien mothership compatible with Mac OS, but despite millions of years of technological advancement, they don't have even the most rudimentary form of a firewall. It's possible in their culture that software hacking was unheard of.
- The flying saucers are also weak to jets crashing into their giant death rays.
- In The War of the Worlds, the aliens are vulnerable to Earth bacteria and viruses. While new beings likely wouldn't be vulnerable to earth's viruses, bacteria would be able to wipe out any species without an adapted (or adequate) immune system. This is because the different ways that bacteria and viruses work. While it's stated to be the common cold in the movie, it could just be a "sinus infection" (bacterial). Any alien species moving to a different planet would be highly vulnerable to any and all new bacteria.
- A blink-and-you'll-miss-it "Achilles Heel" appears in the Jim Carrey movie Liar Liar, where, faced with the prospect of "doing The Claw to [his ex-wife]", main character Fletcher Reed says, "You've found The Claw's only weakness—sub-zero temperatures!"
- The Wizard of Oz: The Wicked Witch of the West's vulnerability to water.
- Parodied in Scary Movie 3. The aliens are fighting the group (though just because strangling is how they say hello), when Mahalik decapitates one with a shovel and says:
Mahalik: I found it! Without their heads, they're powerless!
- Also parodied in Harold And Kumar Go To White Castle, during a psychedelic dream sequence.
Officer Palumbo: Bullets! My only weakness! How did you know?
- Lampshaded and overdone ad nauseum in Mindhunters. The plot of the movie rests on a FBI profiler killer killing other FBI profilers by presenting them in situations where they will have to fall for traps he's devised, because said trap is their weakness. In the end, he dies by getting shot in the head, causing LL Cool J's character to quip "I guess we found out his weakness. Bullets.". However, the killer's true Achilles Heel is time. Everything has to happen on his schedule.
- In Attack of the Killer Tomatoes!, the eponymous tomatoes are defeated by playing the fictional artist Ronny Desmond's new hit song "Puberty Love," which causes them to shrink and become vulnerable to crushing.
- Similarly, in Tim Burton's Mars Attacks!!, the Martian attackers are defeated by playing Slim Whitman's "Indian Love Call," which causes their heads to explode.
- Talos the Titan in Jason and the Argonauts has a near-literal version of this trope.
- Beowulf kills the dragon, by stabbing the small part of its chest to where its heart should be, and he crushes it.
- The Djinn in Wishmaster has one main weakness: he can only use his powers in the service of wishes, which annoys him quite a bit ("Do you have any idea how frustrating it is to have unlimited power, and only be able to use it when some worm asks you for something?"). Without a wish, he's virtually powerless except for his Nigh-Invulnerability. Getting everyone to stop wishing is next to impossible, however. Particularly since what qualifies as a "wish" is pretty arbitrary. Like a woman at a party saying "You can see right through me..."
- Freddy Krueger of the A Nightmare on Elm Street movies is an all-powerful Reality Warper... but only in dreams. In the real world, he is as vulnerable to damage as any normal person, although he's still pretty resilient. The protagonists in the series use this to their advantage several times. In the original movie, Freddy uses it right back at Nancy, since her return to the real world where she can defeat him turns out to still be a dream.
- A rather clever one in Man of Steel, Clark was overwhelmed by his burgeoning Super Senses and other powers and took some time to control them. He realizes in his first major confrontation that Zod and his crew were using sealed atmosphere Powered Armor that minimized the reactions they would get from the yellow sun. By breaking those seals they were overwhelmed just as much as young Clark was. Zod later comments that it is a weakness they will adapt to and Zod later fights Superman with all those same powers.
- The film also offers another natural weakness for Superman besides the stand-bys of red sun energy and Kryptonite. Specifically the atmosphere of Krypton was a lot thinner and Clark had spent his whole life in a much thicker environment.
- Children of the Corn
- In Who Framed Roger Rabbit, a substance known only as "dip" is able to kill otherwise invulnerable toons. It turns out that it is also the Achilles' heel of villain Judge Doom, who is revealed to be a toon himself.
- Leto Atreides II, the eponymous God Emperor of Dune, who combines his body with a sandworm to extend his life by thousands of years and gain immunity to almost every form of physical damage, also inherits the sandworms' vulnerability to water.
- In the Chrestomanci series by Diana Wynne Jones, the Chrestomanci are powerfully magic characters who are nearly invincible due to their powers, and their nine lives. However, every Chrestomanci has one particular weakness.
- In David Eddings' Belgariad, it appears the Achilles Heel of the ancient and evil god Torak is to tell him nobody loves him. As everything he'd done through his existence was to force people to love him, this throws him into an Unstoppable Rage... which causes him to drop his guard. Cue impalement.
- Although it can vary, werewolves are typically weak to silver, touching it causes severe burning.
- In The Lord of the Rings, Sauron is incredibly tough, but if the One Ring he created is thrown into Mount Doom, he will lose all of his power, so that all he becomes is a little formless evil spirit incapable of affecting anything around him forever. Tolkien goes to lengths to justifies this. The original point of the One Ring was for Sauron to gain control over the leaders of Men, Elves, and Dwarves, to whom he had (while in disguise) given the other rings of power. He had to put most of his strength into the One Ring in order for it to be powerful enough to control the others, especially the three Elven rings.
- Then there's Smaug, in The Hobbit. He knew about the vulnerability of his belly and had created what amounted to a waistcoat out of diamonds from his hoard. (How he created this, or attached them, is never explained.) It was this protection that was flawed. There was just one spot in his belly that he missed but Bilbo didn't.
- Generally a Soul Jar is the weakness for anyone who uses it.
- In Animorphs both the heroes and the villains have one:
- For the Animorphs, their weakness is the two-hour time limit they can spend in a morph. If they go over that time limit, they're trapped in morph forever.
- For the Puppeteer Parasite Yeerks, their weakness is the need to leave their host body every three days and swim in a Yeerk Pool to absorb life-giving Kandrona rays. Without doing so, they will die.
- According to Dumbledore in Harry Potter series, Voldemort's weakness is his inability to love.
- Lily Potter's Heroic Sacrifice for the son she loves so much gives Harry a shield that is able to make a Killing Curse rebound and that same shield burns Quirrell's skin when he has been possessed by Voldemort, rendering him unable to attack Harry due to pain.
- Harry Potter and the Chamber of Secrets: His brotherly love for Ron and, to some extent, Ginny, pushes him to go down to the Chamber of Secrets to rescue the girl, and his respect for Dumbledore gives him the things he requires to kill the Basilisk, one of whose fangs he uses to destroy Tom Riddle's Diary.
- Harry Potter and the Goblet of Fire: His parents' ghosts protect him when he has to run away from the cemetery after Voldemort's resurrection.
- Harry Potter and the Order of the Phoenix: When he is possessed by Voldemort, just thinking of the recently deceased Sirius is enough to kick Voldemort out. Also, Dumbledore's love for him stops the Headmaster from killing Harry in the hopes of killing Voldemort (which wouldn't have worked due to the horcruxes.
- Harry Potter and the Deathly Hallows: First, Snape turned spy for Dumbledore when Voldemort targeted Lily Potter, whom he had always loved. Then, Snape protects Harry and helps him to the best of his ability due to his love for his mother (his mistreatment of him comes from his being a look-a-like of James Potter) during all the books. Later, Harry sacrifices himself so that his friends and schoolmates don't die (and thus casts upon them the same shield his mother cast upon him). Much later, Narcissa lies to Voldemort about Harry being alive because she wants to see her son Draco (which is the signal that they are fed up with how Voldemort has treated her). And, in the end, it's Harry's ability to work with all of his friends that allows them to defeat the Death Eaters.
- There is also his reliance on and treatment of the horcruxes. They were supposed to prevent him from dying, and they accomplished that perfectly well. The problems were that: a) He was very lax with their protection at times (giving the diary to Lucius Malfoy, for example), because he had so many, and b) He couldn't tell when they were destroyed and so left his guard down.
- One of 'The Demon Headmaster' books featured a super logical computer which was defeated by all the children in the world yelling pointless anti-logic.
- In Dan Simmons' Illium and Olympos the Trojan war is being deliberately recreated. Part of this involves Achilles being given a sort of quantum invulnerability that ensures he will only every be hurt by an arrow intentionally fired at his heel by Paris, which probably takes the cake for most specific and most inevitable Achilles Heel.
- Fairy folk in the Artemis Fowl series are all susceptible to animal fat. Being exposed to animal fat will suck out all of their magic.
- This becomes a plot point in the final book in the Percy Jackson and the Olympians series. A character who bathes in the River Styx gains the "Curse of Achilles," making him or her a one-man army. However, since humans aren't meant to be invulnerable, the Styx will burn them away if they don't focus on one point on their body to be their mortal point—a literal Achilles Heel, just not at the heel. Percy's Achilles spot is the small of his back; Luke's is his left armpit.
- Although when you think about this, it doesn't make much sense. Achilles's weak spot was on his heel because that was the only part of his body that wasn't submerged in the River Styx when his mother dipped him while holding him by his heel. Unless Percy and Luke are extraordinarily skilled contortionists, it would be impossible for those parts of their bodies to be the only parts that remained above the water.
- The Steel Inquisitors in Mistborn: The Original Trilogy are very dangerous customers, with Allomantic powers as well as superhuman strength and speed. However, the steel spikes that pierce their body are their weakness - if you pull out both the spikes in their eyes, or the one in their upper backs it kills them instantly. Marsh uses this to take out all the Inquisitors in Luthadel near the end of the first book. Of course, when they show up again in the third book, they grew Dangerously Genre Savvy and armored up their weak spot.
- Also, all creatures created with Hemalurgy, Steel Inquisitors included, can be controlled by a Mistborn using Emotional Allomancy along with duralumin. Or by several Soothers or Rioters working in concert, or by Ruin.
- In Aaron Allston's Galatea in 2-D, Red comes from a painting of Achilles and has the heel.
- In The Dresden Files Nicodemus is made invulnerable by wearing Iscariot's Noose, but he's vulnerable to the noose itself, which naturally is conveniently already around his neck.
- Fairies are consistently vulnerable to iron.
- In the Sime Gen series Simes frequently kill Gens by sucking out their Life Energy, but any Gen can kill the Sime first if they know where the Sime's conveniently at hand weak spots are.
- In the last book of The Wheel of Time Padan Fain, aka Mordeth, aka Shaisam had become a borderline Eldritch Abomination with a host of unnatural powers and a small army of the undead at his disposal, and was a genuine threat to the forces of both good and evil- not bad for the snivelling Punch Clock Villain he started out as. However, his original human body, which was at the heart of the shifting cloud of white killer mist that in many ways was really him, remained mortal. When Mat killed said human body, the entire horrible entity was dissipated.
- Legacy of the Dragokin: Due to Jihadain's magic, the Kthonian Knights can survive any injury so long as their heart remains intact.
- Adventure Hunters: No matter how powerful the gargoyle, light will turn him to stone.
- In Those That Wake's sequel, hired goon Castillo has a weak knee.
- In Angel, where Angelus figures out the Beast's weakness:
"I mean, look at this guy, hm? Pretty much the only thing that could do damage to that thick, stony hide...is himself. Or, maybe, I don't know, a piece of himself."
- Doctor Who does this a lot.
- In "The Moonbase", Cybermen were weak against solvents, or as the Doctor would later put it, "cleaning fluid".
- Cybermen were also given an Achilles Heel in the story "Revenge of the Cybermen": gold dust would asphyxiate them. This was not a tremendously damning weakness, since gold is neither common nor easy to form into an effective weapon. In "Revenge of the Cybermen", the Cybermen were Nigh Indestructible even on a planet made entirely of gold, because the locals didn't have the technology to make an effective delivery system for the gold. As the series progressed, gold was promoted to Kryptonite status: in "Earthshock", the Doctor injures, but does not incapacitate, a Cyberman by grinding a gold badge into its chest, but by "Silver Nemesis", Cybermen can be killed by lobbing gold coins at them, or shooting gold-tipped arrows. Gold-tipped arrows are very effective against Cybermen, but, of course, totally ineffective against anything else. It is sometimes joked that had the original series gone on, it would eventually have been possible to destroy a Cyber-war-fleet just by saying "gold" at them. After the show was revived in 2005, a fake website connected to the revival's second series hints that the Cybermen seen in "Rise of the Cybermen" and later episodes had the gold weakness worked out in the prototype stage. It was showed on a computer screen in that episode that the weakness had been worked out. Though not present in the Cybermen themselves, the older programming of the Cyber-Planner in "Nightmare in Silver" made it temporarily shut down when a golden ticket was placed against it.
- In addition, the Cybermen have been vulnerable to emotions in several appearances.
- The Sontaran's 'probic vent'. "Back of the Neck!" Of course bullets work perfectly well too...
- The Slitheen, being composed largely of calcium, can be killed with acetic acid.
- The Daleks were originally vulnerable to turning off the static electricity. They also couldn't climb stairs due to their flat bases and gliding motion, which was made fun of outside the universe and sometimes even in it. However, in the modern reincarnation Daleks can levitate.
- The Macra were helpless without their special gas (which made one wonder how they managed to force humans to start making it in the first place).
- The Ice Warriors are vulnerable to (what else?) heat.
- The deadly sea weed of The Fury from the Deep were vulnerable to Victoria screaming (luckily, she was good at it).
- Autons are also vulnerable to solvents.
- The Nestene Consciousness is susceptible to "anti-plastic".
- The "Seeds of Death" are vulnerable to water.
- The evil computer in The Green Death was vulnerable to logical dilemmas.
- The maggots in The Green Death weren't phased by bullets, bombs, or bug spray, but met a quick end after eating hybrid mushrooms meant to be a meat substitute.
- Mandragora energy is vulnerable to being conducted away.
- The Fendahleen are vulnerable to salt.
- The giant octopus Kroll was vulnerable to... a small stick. Okay, a special stick.
- The Mara is (are?) vulnerable to mirrors and happy thoughts.
- The Sea Devils and Silurians are helpfully vulnerable to a deadly gas which is blatantly introduced at the start of "Warriors of the Deep", then conveniently forgotten about until the climax.
- The Destroyer in "Battlefield" is vulnerable to silver.
- Fenric is vulnerable to puzzles.
- The Master leaves himself vulnerable to happy thoughts in "Last of the Time Lords". In addition, his biggest weakness throughout the series is... the Doctor, the one person he's never fully understood. (One episode of the classic series shows that his worst fear is a room full of the Doctor, laughing at him.)
- In the series True Blood, besides the usual vampire weaknesses (sunlight and silver), since vampires are undead, they can be controlled by a necromancer, to the extent they can be forced awake during the day and made to walk into the sunlight to their demise.
- In The Six Million Dollar Man and The Bionic Woman, extreme cold could make the bionic heroes' parts stop working until they warmed back up.
- In Heroes, Claire Bennet has a Wolverine-class healing factor that can repair her body to brand new after taking the unrealistically extreme amount of punishment that always comes her way. However, if an object is stabbed into a certain spot in the back of her head, she's rendered "dead" until it's removed, and the same goes for anyone who copies her powers. It's implied (and confirmed in an alternate future episode) that if this part of her brain was removed or destroyed, she would die permanently.
- The Blutbad from the series Grimm have a weak spot at the lower right part of their back. If hit there it will stun them for a few seconds.
- Sheriff Lucas Buck's vulnerability in American Gothic is his third eye—if stabbed there, he could be killed. What makes this a particularly egregious example is that not only is there no indication of this vulnerability until the next to the last episode of the show, but what could have been a very cool mythologically resonant plot point is instead wasted twice over: the person who reveals and exploits this weakness is a throwaway character we'd never met until the previous episode and the stabbing doesn't even take, since Buck is revealed alive in his grave at the end of the episode.
- In Star Trek: Deep Space Nine, Founders are almost absolutely immune to physical damage, vulnerable to BIG amounts of radiation or phaser weapons... and can be killed by specific virus. There is another downplayed weakness: Odo has to go into liquid form for 8 hours a day, much like humans need to sleep. In one episode, he was prevented from doing so, and started physically falling apart as a result. This is not a problem for the others and is only a problem for him because of his lack of experience shapeshifting.
- Star Trek: The Next Generation has Data, an incredibly strong, fast, durable, and intelligent android...with an off switch on his side. Flipping it renders him effectively dead until he's turned back on.
- The Borg are near unstoppable forces of nature that assimilate and adapt to everything they come across, but Star Trek: Voyager reasoned that if they can't assimilate it then they can't adapt to it, which is why they were so vulnerable to Species 8472. The Voyager crew, on the other hand, used scientific investigation and creativity, which allowed them to design a weapon to use against 8472. They are also unable to adapt to blades: Worf killed them plenty with those and they never adapted.
- Although not one related to the villain itself, the Goa'uld of Stargate SG-1 have force shields that can be bypassed by slower-moving objects. (Bullets won't work, but a thrown knife will). Later, the Replicators can only be destroyed with projectile weapons. Yes, their only weakness is getting shot. It makes sense in the show. Specifically, energy weapons don't work on Replicators because the machines have energy shields resistance to all forms of harmful energy. However, projectile weapons like modern-era guns do their damage through kinetic energy, which causes the Replicators' relatively fragile bodies to shatter.
- Each Monster of the Week in the short-lived Deadly Games generally could only be stopped in two ways and were otherwise totally invincible. The first varies from villain to villain but is usually elaborate or silly: shoot him with an arrow through the small target on their chest, drop a house on her (a mobile home worked in a pinch), etc. The second is always "foil their evil plan"; they don't get do-overs. Either method makes them vaporize instantly.
- Mighty Morphin' Power Rangers:
- The Warzord Cyclopsis was one of the best things Rita ever deployed, because its computer could adapt to each Zord and Zord formation used, (configuring the shields, targeting, weapons, armor-plate angling and such). However, quickly switching formations enough would overtax this system, causing the computer to lock up due to being asked to do more tasks at once than it was capable of. This allowed the Rangers to beat its restored form, obliterating it permanently.
- Z-putties. In the first fight, the rangers stated they were invincible, until Jason discovered they explore when you hit the "Z" on their chest. Later, kids were able to destroy them launching balls at the "Z".
- Because he was the Sixth Ranger, the Green Ranger was plenty powerful, but because of how he returned to action, he couldn't stay in battle too long or his powers would run out. Come the second season, most of Zedd's early plots were essentially "take out Tommy."
- Power Rangers Lost Galaxy had the Chameliac Warrior who copied the Rangers' powers... that is, until they swapped their attack moves with their friend's moves: Pink used Blue's moves, Green used Yellow's moves... you get the idea.
- The Storm Megazord of Power Rangers Ninja Storm (and it's Ninpuu Sentai Hurricaneger counterpart, Senpuujin) had a Super Mode referred to as "Lightning Mode'/"Senpuujin Hurrier" that purged its armor and made it extremely agile - but only for sixty seconds. After that, it risks internal damage.
- In Power Rangers Mystic Force, the otherwise invincible Megahorn's only weak spot was a small area on the back of his neck. This was carried over from Drake in Mahou Sentai Magiranger.
- In MythQuest, the main characters meet two mythological characters that have this kind of flaw: Baldr and Lleu, from Norse and Welsh mythology, respectively.
- For all their power, Whitelighters and Elders in Charmed can be mortally wounded by arrows tipped with Darklighter poison. Additionally, a wounded Whitelighter/Elder cannot heal themselves in this event (but another, unwounded one can).
Mythology and Religion
- The name for this trope is the Greek hero Achilles. In Homer, he's not invulnerable (he bleeds from a minor spear wound). Classical Greek art depicts Achilles being killed by an arrow to the body. But Statius, writing in the 1st century AD (900-some years after Homer), gave him a colorful superpower. According to Statius's account, Achilles' mother, the nymph Thetis, dunked him in the River Styx to make him immortal. However, she wasn't able to dunk the foot she held him with, since as a goddess, she could not bear the touch of the Waters of Styx. Quite naturally, he was killed by a poisoned arrow to the heel, courtesy of Prince Paris of Troy. For some reason she didn't think to dunk him, pull him out, dry him up, flip him over and dunk the dry foot.
- An alternate version has Thetis annointing Achilles with ambrosia and burning the mortality out of him over a fire. Her husband Peleus happened to walk in on her and, well, there's a reason the two are living separately by the time Achilles grows up.
- Also from Greek myth, the Gigantes were the children of Gaia and only had their supernatural powers when they were touching the ground. Heracles defeated one of them by picking him up with one hand and beating him with the other. Other stories say the true Gigantes could only be killed by weapons of a mortal being. Hence, the gods invited Herakles (or perhaps that was the entire point about their affairs with mortal women). Some Gigantes were defeated by gods, but not killed - one is still alive, breathing fire under Etna.
- In the Persian epic The Shahnameh, the Persian prince Esfandyar bathed in a pool of invincibility, but kept his eyes closed as he submerged himself. When he picks a fight with the hero Rostam, he gets killed by an arrow through his eyeballs.
- In the Biblical Book of Judges, Samson loses his Super Strength when Delilah cuts off his long hair. Notice that this is hinted to not be a 100% Achilles Heel. Hot-Blooded as he was, Samson had broken all of the other rules God gave him to keep his Super Strength and telling Delilah about his hair (and how he was consecrated to God) was figuratively the last straw. In a nutshell, the big three vows require Nazarites to abstain from alcohol, to not cut their hair, and to avoid corpses. Apparently Samson was known to have had wine in the past, touched (and consumed honey out of) a lion's corpse and there was that whole 'beat hundreds of Philistines to death with the jawbone of an ass' bit, which doubtless left him around a number of dead bodies afterwards.
- When Baldr of Norse Mythology started dreaming of his own death, his mother went around to every single thing in existence and made them swear an oath to never harm Baldr. Presto, invulnerable god, right? Not quite: she forgot to ask mistletoe, since it seemed too small and shriveled to be a threat. When the rest of the pantheon decided to make "Let's throw things at Baldr" into their favorite party game, Loki (who was jealous of the attention accorded Baldr) tricked the blind Höđr into shooting a Mistletoe arrow at Baldr...
- In the German poem, the Nibelungenlied, the hero Siegfried bathes in the blood of a dragon after he's slain it, and becomes invincible as a result. However, a leaf had stuck to his shoulder, and thus left a spot there untouched by the blood... and yes, the similarities between him and Achilles have been noted before.
- Russian mythology features Koschey the Deathless, an eldery evil warlock who has his death stored separately from him. His death is a needle hidden in an egg, that's inside a duck, that's inside a hare, that's inside a chest, than hangs on a great oak, that grows on a distant island. To kill Koschey, a hero must break the egg and/or the needle.
- The Tlingit people of the Pacific Northwest have a monster with an Achilles Heel: Once there was a giant that ate people. A man decided to kill the giant, so he played dead where the giant walked every day. The giant found him, brought him home and left to get firewood. The man jumped up, threatened the giant's son with a skinning knife to make him tell where his father's heart was. It was in.... The left heel! The giant returns, and the man stabs his heel. The giant screams, "I will eat your people forever!" But the man chops him into pieces and burns him. The ashes become mosquitoes, which form into a cloud and laugh, saying "I told you: I will eat your people forever!" Then the man looks on his arm, which has a mosquito on it...
- The Folklore Of Discworld mentions one British town's story of a Nigh Invulnerable dragon that had only one unarmored spot on its body, which was its anus. It was slain by a hero's well-placed (and spike-booted) kick under the tail.
- Basketball player Shaquille O'Neil (or Shaq), one of the best players in NBA history, had an infamously poor free throw percentage. The best way to keep Shaq from steamrolling you was to intentionally foul him, forcing him to shoot free throws that he'll probably miss. This tactic became known as "Hack-a-Shaq." Interestingly, Shaq was a consistently decent-to-good free throw shooter in practice throughout his career; something about the pressure of being put on the spot in a game situation always threw him for a loop.
- Lebron James, a seemly unstoppable force, was exposed as a poor mid-range shooter during the Finals of the 2006-07 season. He's since corrected this problem, however; as the Finals during the 2012-13 season would prove. And both against the same Finals opponent, the San Antonio Spurs.
- In the world of boxing, a large number of knockout artist often have weak chins that make them just as vulnerable to getting knocked out themselves.
- Dungeons & Dragons: many monsters have specific weaknesses that either do more damage than normal, or are necessary to even be able to kill them. The most famous is arguably the troll, which in most editions can't be killed with just standard weapons, but that also needs to be burned with acid or fire for it to permanently die. Unconventional tactics can also exploit certain weaknesses, or at least find other ways to kill them. Also included are demons/devils vulnerability to certain metals such as cold iron and silver
- Virtually any named enemy in Deadlands will be Nigh Invulnerable, except for one weakness somehow obscurely related to its past. The list goes on: Stone, Raven, the Bishop, prominent Whateleys, Grimme, Death, War, Pestilence, Famine ... In fact, it's so common that one of the most coveted abilities of arcane characters is the rare ability to intuit these weaknesses. (That's part of why the Badass Normalposse keeps the bookworms around.)
- Champions was the first ever Tabletop RPG to feature intentionally taking weaknesses (called "Disadvantages" in the rules) as a part of the character creation process. The disadvantages "Susceptibility" (which causes a character to take damage from something other characters find harmless, such as Superman's reaction to Kryptonite or a vampire's taking damage from holy water) and "Vulnerability" (which multiplies incoming damage from certain types of attacks, such as a werewolf's vulnerability to silver) were specifically created to mimic an Achilles Heel.
- Shadowrun has the Allergy disadvantage, which comes in three grades, depending on the effect of contact with the substance: mildly annoying, exceptionally discomforting, and physically harmful. Shapeshifters automatically have Severe Allergies, typically to silver, vampires have Severe Allergies to sunlight and Moderate Allergies to garlic, etc. The really silly thing is that the rulebook has some recommendations for allergies, which include seawater and oil.
- Yozis in Exalted can be sent through an agonisingly painful and debilitating death-and-rebirth cycle if you take out their fetich soul. It is worth noting, however, that this is often much harder than it sounds.
- Arcueid Brunestud, and presumably all the True Ancestors from Tsukihime. Normally Arc in particular is all powerful, but thanks to the protagonist Shiki cutting her to pieces early on in the game she's usually pretty weak. We finally see her true abilities at the end of the Ciel route, when she goes batshit crazy after Shiki decides that cutting her neck open is a good way to reject her. Shiki only wins when he remembers that True Ancestors get their power from the earth itself, so he kills the earth beneath her to cut her away from her power source.
- Gilgamesh in Fate/stay night has the two most broken Noble Phantasms in the game. One of them is beamspamming Noble Phantasms and the other is
some spinny drill sword thing Ea, an anti-world Noble Phantasm that absolutely dominates Excalibur. Oh and he can use them both all he likes. Weakness? He's an Archer, not a swordsman, so all he can do with those swords is beamspamming them instead of using them properly. Much more importantly, he has an ego so larger that it's even bigger than his ego. Wait. But anyway, he never takes any fight that he's in seriously until he's in mortal peril. Or pieces.
- In Sluggy Freelance, Aylee's crab-like transformation (actually a clone of Aylee) is nearly invincible. Her shell can take just about anything the characters can throw at her, but she can be hurt along her extendable neck.
- Horribus is also only vulnerable on certain parts of his body. Even when Torg uses a magic, kill-anything sword, he can still only take Horribus down by either decapitating him or stabbing him right through his soul (located roughly in the center of his chest).
- Frans Rayner in The Adventures of Dr. McNinja is vulnerable on only one place on his body (his right butt cheek). However, the protagonist (who witnessed his defeat as a boy) strikes the same place 25 years later and fails... Rayner had moved it to his left eyebrow. Then in yet another encounter, it's revealed that following his previous defeat, Rayner moved it again, into his right leg, which he then had amputated.
- From 8-Bit Theater, "A spear? Through my brain? My...only...weakness..!
- Similar to the Z-Putty example, Chris-Chan Sonichu of Sonichu had his main weakness be the white markings on his chest. However, it was rarely struck in the entirety of the series, making it a moot point.
- MS Paint Masterpieces Enker's Spear, when broken, causes him to explode.
- In Pacificators, those with powers cannot use their powers infinitely; their bodies will eventually run out of energy, causing them to black out. If they persist, they may even die. note
- In Darwin's Soldiers, Dragonstorm experiments' only weak point is the back of the net, since this is where their neural net connects to the rest of the body. Said weak point is ridiculously hard to hit, however, since they're usually running towards you, and they're naturally armored.
- Being one of the most famous memes ever, Achilles' heel had a body part named for it, namely, the Achilles Tendon. Sever it, and you won't be walking again for a long, long time.
- Tendons in general are strong but have very little blood supply and heal very slowly. They also get stronger in response to exercise very slowly compared to the muscles they connect to. As such, a common and serious source injury of people who have taken up a new sport and don't know their limits is to have their muscle strength in the required muscles become sufficient to injure the weaker tendons they connect to.
- Not to mention joints, eyes, pressure points, the throat, the groin and the spine, especially near the base of the head are all weak points that martial artists take advantage of to one shot their opponents, it doesn't matter how strong you are if someone hits you in the joy zone.
- There's a fraction-of-a-second interval of the human heart's contraction cycle during which a sudden impact to the sternum can disrupt the electrical signals of the natural pacemaker. Ventricular fibrillation sets in, and is usually fatal without immediate medical intervention. Called "commotio cordis", it's most commonly seen in athletic accidents with boys or youths whose sternal tissue hasn't entirely finished hardening from cartilage to bone.
- While most Nintendo productsnote are literally capable of taking a head-on tactical airstrike and still functioning perfectly, most of the DS line features an Achilles' Heel in the form of the hinges, which are not only destructible, but quite vulnerable and can in fact eventually break from overuse.
- The cobra is a Bad Ass deadly snake from India with only one weakness. It strikes opponents rather slowly. Thus, the agile mongoose is able to defeat the cobra by jumping out of the way when it strikes and leaping up to bite the head when the snake is drawing back from the strike. Believe it or not, the cobra often manages to bite the mongoose once, but since the mongoose has a partial immunity to the snake's venom it takes more than one bite to kill one, and the cobra usually tires out after it manages to bite once. In any given confrontation between an Indian Cobra and an Indian Grey Mongoose, the mongoose tends to prevail three out of five times.
- Mongooses in turn have an Achilles Heel when it comes to the kinds of snakes they can kill. Cobras are fast-moving snakes, but they have slow and predictable strikes, which is their Achilles Heel. In contrast, vipers are sluggish, slow-moving snakes with wickedly fast and unpredictable strikes. That's why, in a fight against a viper, the mongoose loses 95% of the time. Additionally, mongooses have another Achilles Heel in that they are only resistant to the venom of cobras and their close relatives. This leaves them susceptible to the venom of other poisonous snakes that they share their range with, such as the black mamba. There was once an attempt made to reduce populations of fer de lance vipers on an island by introducing a population of mongooses. It was a disaster. The mongooses were all defeated by the snakes and domestic cats were used instead.
- Crocodiles and alligators have an Achilles Heel in their jaws. While the muscles they use to bite are very strong, the opposing muscles used to open their jaws are much, much weaker. A decent elastic band can turn a crocodile from deadly prehistoric monster to walking handbag. The same is true on a less impressive scale with crabs and lobsters.
- Sharks have a similar weakness: if you manage to flip one upside down, it will enter a state of "tonic immobility" and become paralyzed. Some orcas managed to figure this out to hunt sharks.
- For many types of vehicles in combat (aircraft, ships, and ground vehicles included), traditional weakpoints include the fuel (flammable), ammunition (explosive), and crew (Squishy).
- A major weakness for Japanese warplanes in World War II was their lack of self-sealing fuel tanks or armor for the pilots, meaning it was rather easy for an enemy pilot in a better-protected aircraft to set a plane ablaze or perforate the cockpit. It only made things worse for the Japanese that American and British fighter planes tended to be significantly faster and more heavily armed than theirs were.
- For warships, the biggest weakpoint has always been the magazines, where their stockpiles of ammunition are kept. Even sailing ships in the days of Wooden Ships and Iron Men were known to occasionally explode violently. Throughout the 20th century, warship armor design has evolved to the point where if any part of the ship is armored at all, it will be the magazine, at the expense of any other part of the ship, due to the sheer destructive force of that much ammunition going off due to a fire or an unlucky hit.