A tendency for villains to carry a vial of the antidote to the poison he or she just gave the hero under their shirt for absolutely no reason whatsoever.
It can go down in several ways. One commonly used method is for the hero to spend the episode trying to scrounge up the ingredients to the cure from scratch, quickening the drug in the process, only to fail and be informed by the villain that they had it all along. Is also regularly executed during a trade off, with the villain receiving what they want but Withholding the Cure. One has to wonder why they felt the need to bring the real deal if they were planning on cheating out the hero anyway. Another more humorous subversion is for the villain to reveal the vial and have it snatched from or knocked out of their hand before they can even get the gloating out.
Some may try to Hand Wave it by giving the villain a sadistic thought process, demonstrating that they enjoy recounting the agonizing death awaiting the hero only to dangle the one thing that could save the hero's life right in front of their face. Nonetheless, they pretty much do it so that the hero or his companions can steal it and use it Just in Time. It makes a bit more sense when the villain is using the poison as a form of blackmail, fully intending to hand over the antidote as soon as the hero has given him what he wants in exchange. (This doesn't explain, though, why the villain would need to carry or hand over an actual antidote...)
There's also another possible Hand Wave, one that can be a reasonable justification in the right conditions. Accidents happen, and if you're carrying poison around with you accidents can be fatal. Someone might get clever and try a Poisoned Chalice Switcheroo. A case of friendly fire might lead you to inadvertently hitting the wrong person with your poisoned weapon. People who are careless with weapons might even manage to injure themselves with their own poison. In any of those situations, you might really need to have the antidote on hand; the villain might just want to be prepared in case he or she is accidentally poisoned, well aware of the possibility of Death by Irony. However, the true Evil Genius' way to prepare for this eventuality is to build up an Acquired Poison Immunity.
The concept of an instant antidote is itself a form of Applied Phlebotinum. In real life, even if a toxin does have an effective antidote its action will rarely be as fast as depicted in Hollywood. For example, atropine blocks and counteracts the symptoms of nerve agent poisoning, but it does not actually remove the toxin from the body or heal damaged tissue. Even with an antidote, a poisoned patient may require extensive hospital care. Poisons in Hollywood also typically have a time limit during which the victim will feel no symptoms until the time limit expires, at which point they suffer a Critical Existence Failure.
- Somewhat justified in the first episode of Pumpkin Scissors: a) since the poison was airborne, having some antidote on hand for accidental exposure was a good idea, and b) the antidote was originally stashed in their base where it would be hard to get at. Why the villain brought it with him for the final showdown remains unexplained, though.
- In the anime Bleach, one of the shinigami captains, Mayuri Kurotsuchi, possesses an ultimate attack which creates all sorts of nasty chemicals, at least one of which is poisonous. Uryu, who had the misfortune of fighting Mayuri, gets poisoned, but after the captain leaves, his subordinate/Opposite-Sex Clone Nemu (who, like Mayuri, is immune to it) gives Uryu the antidote.
- This drove the plot of an episode of Cyborg 009, as the heroes had to stop an evil syndicate who had stockpiled an antidote to a deadly disease. The bad guys were trying to sell the stuff on the black market. The Chick and Team Mom of the group (a girl who happens to have Super Senses that make it easier for her to find the antidote and the bomb) gets pissed off as she finds out, and it triggers her Crowning Moment of Awesome.
- In Hunter × Hunter, Gon risks his life to search a villain's corpse for an antidote to the snake venom that is killing his friend, getting himself bitten in the process. When another companion asks how he knew it would be there, Gon replies that it's only common sense that anyone who uses venomous snakes as the basis for his attacks would carry the antidote: not only because of the chance of being bitten himself but to act as a bargaining chip against enemies who have been poisoned.
- Done interestingly in the third Death Note movie L: change the WorLd where a group trying to wipe out humanity for the sake of the environment develop an incredibly spreadable and fatal disease. They are rendered unable to use it near the beginning when the antidote is destroyed and therefore if they released it they too would die. Though in the end, the leader releases it anyway because (unbeknown to their henchmen) they are willing to die for their cause
- In Get Backers, Himiko Kudo - who isn't really a villain most of the time, just the "opposition" - always carries an Antidote Scent to counteract any effect by her poisons. Perhaps justified in that she sometimes used them on herself and usually wants to stop breathing fire at some point.
- In Flame of Recca, Mikoto of the Uraha wields detachable claws that poison the enemy and claims not to be carrying the antidote. In response to this, Fuuko steals one of the claws and stabs her with it. Naturally, Mikoto produces the antidote almost instantly, which Fuuko also steals.
- Subverted in the Ninja Scroll movie, where Tokugawa spy Dakuan forces Jubei into his service by hitting him with a poisoned shuriken (ironically saving his life from a hypnotist in the process). When Jubei tries to poison Dakuan with the same shuriken in return, Dakuan replies that he already got rid of it. The antidote is surprisingly to be poisoned by Jubei and Dakuan's poison-laden ninja ally Kagero through some type of sexual contact. Since Dakuan is technically a good guy he willingly gives up the antidote near the end of their mission.
- At first subverted, then played straight in Busou Renkin. When Tokiko gets implanted with the homunculus core early in the series, Koushaku Chouno told Kazuki he had the antidote in pill form, only to be a fake. Later, in the first showdown between Chouno (now Papillon) and Kazuki, Papillon swallows the key to the box containing the actual antidote, telling Kazuki he must kill Chouno if he wants to save Tokiko.
- In the Yu-Gi-Oh! manga, Mokuba challenges Yugi and Jounouchi to a game of food roulette, where they eat what's in front of them. Jounouchi eats a poisoned meal, and Mokuba reveals that he has the antidote to the poison, which Yugi will have to defeat him to get. Yugi wins despite Mokuba's cheating, and gets the antidote for Jounouchi while Mokuba eats the other poisoned meal. He survives, possibly because one of his servants had another antidote.
- Hanzo of Naruto carried around a vial of antidote to the poison his body produced because his breath would uncontrollably exude poison if his respirator came off. Notably, this is never shown as backfiring: when a poisoned enemy of his got the antidote it was because Hanzo GAVE it to him.
- Vincent in Pandora Hearts poisons Sharon and Echo to get Break to destroy Alice's memories, promising him the antidote if he does so. When he does, Vincent tries to throw the antidote off a balcony, only to have Echo stop him.
- In Science Ninja Team Gatchaman, the team fights Galactor who is polluting the oceans and conventional attacks simply accelerate their aims. However, they managed to stop the operation and in the process, inadvertently make Galactor spill their countermeasure they happen to be carrying on board.
- Justified in Jojos Bizarre Adventure. For the sake of a challenge, the villains poison Joseph to impose a time limit on him, and to survive he'll have to defeat them and claim the antidote they're carrying.
- Lupin III: Island of Assassins has the taunting-the-hero version. Doc has the antidote to the island gas on him during the final confrontation.
- Inverted in an old issue of Marvel's Captain America, where the supervillain Cobra appears to pull just this ploy to get his (likewise villainous) nemesis Mr. Hyde off his back. In fact, Cobra was bluffing about the poison all along...but the supposed "antidote" turned out to be powerful knockout drug.
- Also used in a somewhat more recent Avengers issue, when a flesh-eating bacteria started spreading outwards from Mount Rushmore in a fast-moving red cloud. Cap's archenemy the Red Skull had the bacteria engineered to wipe out "lesser races", which backfired when it turned out that the bacteria ate anybody. The Skull did immunize himself somehow, and the day was saved when the Avengers caught him and had scientists take his blood for a cure.
- In one Squadron Supreme, the time-traveling villain the Scarlet Centurion torments Tom Thumb with the cure for cancer, withholding it when Tom Thumb refuses to poison fellow team-mate Hyperion. Ultimately deconstructed when it is revealed that the "cure" is common Aspirin, which is good enough to knock cancer out of the heavily-engineer people of the Centurion's future, but useless to Tom after his Faustian bargain.
- In the Harry Potter fic Perfect Situations, in order to get Draco Malfoy and his goons to leave her alone, Daphne Greengrass force-fed him what she claimed was a poison that would be lethal in ten months' time and said that he could have the antidote at the end of the year if he behaved himself. Actually, it was all a bluff.
- In The Emperor's New Groove, Kuzco spends most of the movie trying to get back to his palace so he can force Yzma to turn him human again; Yzma has potions to transform anyone to practically any shape. When he finally gets there, he has no idea which one is the "human" potion, and steals them all, which results in a transformation fight with Yzma similar to the Toadstool from The Sword In The Stone. At the end Yzma is turned into a kitten, so they're both really fighting over the same "antidote".
- In the opening of Indiana Jones and the Temple of Doom, Dr. Jones trades the remains of Nurhaci to gangster Lao Che for a large diamond, when Indy is poisoned by Lao Che and offered the antidote to intimidate him into giving back the diamond. Naturally there's a fight and Lao Che drops the antidote, allowing Indy to drink it and save himself (but he loses the diamond in the fight).
- In the outlandish Batman & Robin film, Mr. Freeze has a partial cure for the disease his wife is suffering from in his suit. Batman needs it for Alfred, who suffers from the same disease.
- Turned inside-out in the otherwise trope-tastic Mission: Impossible II. A scientist creates the ultimate flu vaccine — also producing the ultimate superflu in the process. Things are the right way around once the villain gets his hands on the suitcase. The villain also had an interesting way of selling the vaccine, as surprisingly, he did not ask for a ransom.
- Backwards. He had to create the ultimate flu virus to create the ultimate flu vaccine. Which, while being a horrible violation of the Geneva Convention, is actually pretty consistent with the production of some types of vaccines. Minus the part about creating a supervirus, anyway. Dead or dying samples of the virus are prime examples of a vaccine.
- In both Escape from movies, poor Snake Plisskin has something injected into his body that will kill him if he doesn't accomplish his mission and get back in time to have it deactivated/cured. Subverted in Escape From L.A. when Plisskin is told the "lethal virus" is really nothing more than a rather strong case of the flu.
- Used frequently in the Saw franchise. "There's a slow acting poison coursing through your bloodstream, which only I have the antidote for..."
- In Van Helsing, Dracula has a cure for lycanthropy, though for a very good reason. He's weak to werewolves, so it acts as an insurance policy.
- The Radix: an example by a hero. John Brynstone injects the Big Bad with poison and interrogates him by promising the antidote. At the end he confesses that he was bluffing: "poison" was actually saline salution.
- Played straight and subverted in Best Served Cold by Joe Abercrombie: The poisoner Morveer regularly carries antidotes to poisons that he lacks immunity for on his person. He uses this to his advantage when his assistant, Day, attempts to kill him. He retaliates by cutting her with a poisoned knife and dangling the antidote in front of her. It turns out that the knife was unpoisoned, and the "antidote" was the real poison, which Day gratefully swallows.
- Subverted in The Lies of Locke Lamora: The titular hero has been given a slow-acting poison by the mastermind of the secret police, a frail old lady. She shows him the antidote in her hand and informs him that he will only receive it if he cooperates. He proceeds to punch her out and grab the antidote, commenting on how she thinks she's a lot more powerful than she really is.
- The villain in the sequel is a little smarter, keeping the Alchemist carrying the antidote well guarded at all times and only carrying enough antidote for one person.
- Naked Empire, the eighth book of the Sword of Truth series averts the trope. The moment the villain obtains the only antidote for a poison the main hero ingested, he dumps it in the ground without any ceremony or even letting the hero get within ten kilometers of it. Unfortunately for him, a Deus ex Machina saves our valiant hero in the last moment.
- Artemis Fowl uses the blackmail version on a decrepit alcoholic sprite in the first book, "poisoning" her with holy water to force her to let him look at her Book (which contains the secrets of the fairy people) in exchange for an antidote - which he faithfully administers once he has what he wants. And since the fey had been addicted to alcohol for ages, he also slipped in the ultimate hangover cure, with an added amnesiac/knockout drug. As to why he didn't just kill her, the Book has to be freely given, so that wouldn't work. Butler does question why Artemis didn't finish her off afterward, but this hints that Artemis isn't actually as cold hearted as he likes people to think he is.
- Subverted in the War of the Spider Queen series, where not only does Quenthel have no antidote to the poison she administers to a traitorous student, it is not even a poison per se, but rather an alarming-but-non-life-threatening overdose of alertness potion.
- Subverted in The Amazing Maurice and His Educated Rodents Keith and Malica give the two Mooks poison, and then offer the antidote in return for information and being set free. Subverted when it turned out that both poison and antidote are actually laxatives. The lesson here is do not mess with Discworld heroes.
- Subverted in the Riftwar book Servant of the Empire: an assassin takes the antidote before drinking poisoned tea along with his victim, but it turns out to not be the antidote. The subversion kicks in when it's pointed out by the victim's spymaster searching for a cure that the antidote bottle was convincing enough to be genuine, so all they have to do is find the apothecary who made it, as he can clearly make the antidote or he wouldn't have an officially-stamped bottle for it in the first place.
- In Deeper of the Tunnels series, during the climactic confrontation, the Big Bad casually informs the hero that she is carrying both the world-destroying super plague and its cure on her person; what's more, hers are the only samples in existence, so losing either of them would completely ruin her evil plan. Must've been carrying the Villain Ball as well...
- In The Pearl, the local doctor finds out that Kino's son has just been stung by a scorpion and that Kino has acquired a large pearl which is expected to sell for a lot of money. The doctor promptly starts implying that even though the baby appears healthy, he could suffer side effects from the sting later and Kino had better let him give the baby a shot. Cue some time later, when the baby is clearly sick and the doctor shows up and gives him another shot that fixes it. While it's not stated if it's the case, it's heavily implied and Kino certainly believes that the doctor made the baby sick and cured him just for money.
- In one of the Spellsinger novels, Jon-tom and his friends go on a perilous Fetch Quest to find a cure for Clothahump's terrible illness. It later turns out that Jon has had that very medication with him all long, having brought it with him from our world. Even worse, it's only aspirin, as Clothahump was faking to force Jon-tom and the others to undertake a journey he knew they'd surely refuse otherwise.
- Subverted in Cornell Woolrich's "After-Dinner Story." A man gathers together everyone who was present during his son's alleged suicide, and explains that he knows one of them murdered the young man, though he is not able to prove it to the law's satisfaction. He has therefore arranged for the guilty party — and only the guilty party — to be poisoned, and he is making the antidote available so that the murderer will have to make a choice: expose himself, or die outright. Finally, someone takes the antidote. The old man then reveals that he didn't know the killer's exact identity, and had to resort to this ruse to discover it. No one was poisoned to begin with: the supposed antidote was the poison.
- A greedy doctor purposely infects the crew of Moya on Farscape so he can charge them a huge fee for the cure. Which only he knows how to make.
- Once again, Star Trek has done this one (in The Next Generation episode "The Most Toys") where a planet had been poisoned by a substance that had a rare antidote. It turned out the person they bought the antidote off was the villain who had poisoned the planet in the first place, using the rarity of the antidote as a way of gaining access to the Enterprise, kidnapping Data and tricking the rest of the crew into thinking he was destroyed in an explosion. The crew only cottoned on when they arrived at the planet and learned for the first time that the poisoning was so specific in quantity that the trader had mysteriously managed to give them the perfect quantity for curing it, something he couldn't have done without knowing in advance the exact level of poisoning they needed to cure.
- Battlestar Galactica (2003): Gaius Baltar injects Chief with a fast-acting poison, then injects him with the antidote after Chief's girlfriend Boomer tells how many Cylons have infiltrated the fleet. Justified, since Baltar's aim was to get information from Boomer, not to kill Chief. Subverted, because Baltar was working for the good guys.
- Played with in Get Smart. When Smart is given a 24 hour poison, he ultimately gets the antidote by poisoning his poisoner with a concentrated sample, forcing him to run to his lab to administer the antidote, while Max follows. The two fight over the antidote but both fall unconscious before they can drink it. Fortunately for Max, the antidote they were manufacturing at CONTROL is completed in time.
- One particular villain on Chuck poisons several characters with a truth serum that also eventually kills you. He not only carries the antidote on his person but has more of it stored in his apartment.
- Given a twist in the final episodes of Season 3 of Buffy the Vampire Slayer in which Faith shoots Angel with a poisoned arrow. Turns out, she is carrying the antidote: her blood. Angel can only recover by draining the blood of a Slayer.
- In one episode of MacGyver (1985), the villain tries to get out some information from Mac by injecting a poison in him that kills him in 24 hours. Mac tries to steal back the antidote instead.
- A good reason for this trope is given in BBC miniseries I, Claudius. Two notorious poisoners meet.
Martina: I never bothered much with antidotes.
Livia: Well you never know, one day some fool of a slave will get the bowls mixed up.
- On Human Target it's discussed: A poisoned character (who was poisoned to death) is said to have believed another character had the antidote. Winston thinks this would be ridiculous, and Guerrero says it's common practice: carrying something so dangerous, you'd want an antidote on you.
- In the live action Zorro show, a government official poisons Zorro. Zorro manages to get a sample of the poison, but quickly realizes that he'd die long before he could figure out what the antidote was. So he arranges for the official to be stuck with a dart marked with his trademark Z. Thinking that Zorro had just given him the same poison (the dart was actually harmless), the official fled to the nearest source of the antidote, allowing Zorro to follow him and take it for himself.
- An interesting case in The Invisible Man. An episode has Bobby accidentally injected with a serum that turns him into a genius. However, as evidenced by serum's test subjects, the "enhancement" eventually burns out the brain. When faced with this, Bobby reveals that he has figured out the antidote with his new intelligence, but he's not going to use it even at the cost of his own life, as this would mean going back to his average old self. Darien forces his hand by injecting himself with the serum, knowing that the presence of the quicksilver gland in his head will make the serum fatal to him. Thus, Bobby is forced to choose between his intelligence and the life of his friend. Naturally, he chooses the latter.
- Dungeons & Dragons
- In early edition adventures, whenever the PCs encountered a creature that turned its opponent into stone it would often have a magic item that reversed the effect, such as a scroll with Stone To Flesh spell(s). One example is in the Judges Guild adventure Dark Tower. In one room is a medusa guarded by an animated statue. If the statue and medusa are defeated, the PCs will find a scroll with Stone to Flesh spells.
- Fourth edition. Almost every monster that can afflict you with something nasty (such as petrification) has the means to undo that effect when the monster is slain, e.g. because some body part is the antidote. The weirdest example is the Rust Monster, that destroys your equipment (not technically poison, but certainly a nasty lasting effect), but when killed will drop precisely enough money to buy a new copy of whatever was destroyed.
- The cave fisher monster fires an adhesive filament that wraps up opponents and is dissolved by alcohol. The cave fisher's blood has a high alcohol content, so after it's killed its blood can be used to remove the filaments it created.
- Module S4 The Lost Caverns of Tsojcanth. When a roper's tentacles hit a person, the victim loses half of their strength for 1-3 hours. One cure for the loss is the magical substance Keoghtom's Ointment. One room in the Caverns contains two ropers, and another nearby cavern has two jars of Keoghtom's Ointment.
- The The Elder Scrolls series has an in-game book titled A Game at Dinner which Subverts this on a Batman Gambit scale. A Dunmer (dark elf) spy is writing a letter of resignation from espionage, and explains why. He was invited (along with several other Dunmer and at least one human) to dinner by Hlaalu Helseth, the head of the House the narrator is spying on. The narrator describes having seen a renowned alchemist (who makes exceptionally unpleasant poisons) visit the host. The narrator attends the dinner, and fakes eating and drinking. After everyone has eaten, Helseth announces that the disloyal have been given a fast-acting poison, the faithful have been spared, and the antidote is in a broth he had just had brought out (there was enough food available at the feast that nobody would have any other reason to drink any). The narrator wonders how this was possible, as all ate from the same plates and drank wine from the same chalice. Helseth announces that the utensils were actually poisoned, so even feigning eating would poison you. Due to this, not only would you die, but you would have "sadly, missed an excellent roast." Eventually, one of the human guests jumps up and drinks a large quantity of the broth, and then confesses his espionage. Helseth smiles when he finishes, and explains that the "antidote" was actually the poison, and that he does NOT, in fact, have an antidote to it. The narrator finishes his letter of resignation by informing his superiors that he sincerely does not want to describe the agony in which the poor man died, and that the paymaster to whom the letter is addressed does not want to know.
- In Shadow Hearts: Covenant, after Yuri is infected by the Mistletoe Curse by Sapientes Gladio, the heroes travel halfway around the world tracking down the leader so they can demand a cure. When they finally corner him, they learn that there is no cure.
- Subverted in Advance Wars: Days of Ruin. Caulder/Stolos brokers a deal with the egoistic mayor, exchanging the mayor's cooperation for the antidote to a bio-weapon he's infected the entire cast with, which he just so conveniently happens to be carrying on his person...
Caulder: Oh, and that medicine you took was not the antidote. Hello? Can you hear me? Mr. Mayor? ...Fascinating.
- At one point in Wild ARMs 5, Pastel, a little girl the group, especially Rebecca, befriended, becomes ill with a commonly incurable disease, so they use an earlier plot point and go back to a Veruni-infested city to ask Persephone, who is a villain to some degree, but the heroes really don't know that yet, for an antidote. She does give them the antidote...for Veruni. Pastel is a human, so taking a Veruni antidote would obviously have fatal side effects for a human, as Carol tells them a little later.
- While monsters in Final Fantasy X don't carry actual antidotes, they carry items that cause a status effect (bees carry poison-inducing items, etc.). Strangely, both crafting a piece of armor resistant to this status change and crafting a weapon that causes the effect requires large quantities of the antidote, and the item itself for the more powerful version.
- In Resident Evil 4, Saddler conveniently keeps a fully functioning and barely protected Las Plagas removal device in his headquarters which Leon and Ashley find just in time. In-game files suggest the reason he had it was he was using it to research a way to make the parasites immune to the device.
- A Justified example happens in Assassin's Creed: Rogue when Shay confronts Hope. She fills the room they are in with a poisonous gas after taking an antidote so only Shay is affected by it. That still doesn't explain why she didn't just throw the vial so Shay couldn't use it.
- A lot of monsters in Terraria inflict various nasty status conditions. However, they have a small chance of dropping an item that gives you immunity to their respective debuffs. Even better, you can combine several of them into one item for maximum immunity.
- Downplayed and justified in the Metal Slug series with the zombies. Only the scientist zombies will drop a medkit that will turn a zombified player character back to human.
- Defied (in a fashion worthy of Ozymandias himself) in this Order of the Stick strip.
Elan: Give me the antitoxin! I know you have one!Kubota: Twelve Gods, why would I be carrying the antitoxin on my actual person? I drank it twenty minutes ago, it will be effective for the rest of the hour.
- Played straight in this one (Although it isn't technically poison, it's a close parallel).
- Justified in that a Scroll of Break Enchantment would be more than just the "antidote" to that particular spell.
- Played straight in this one (Although it isn't technically poison, it's a close parallel).
- In Girl Genius Smoke Knights carry antidotes and test kits for a number of Smoke Knight poisons. Justified in that Smoke Knights work for more than one faction and they end up working against each other fairly often.
- Averted in Jackie Chan Adventures: Valmont infects Jackie with a poison that will turn him to stone, but a) he points out that he isn't stupid enough to be carrying the antidote b) In the final showdown, his goons use the antidote on a fly to prove they have it, and seem willing to give it (until they notice the ransom isn't complete).
- Tarantulas does this in an episode of Transformers: Beast Wars. In fact, he's defeated by an effect of the very virus he infected Rhinox with, combined with some hard-to-digest vine vegetables. It's not pretty.
- In another episode, Scorponok plants a bug on Optimus that is supposed to make him cowardly. There is an antidote, which Megatron keeps and wants to use as a bargaining chip, expecting the now-pacifist Optimus to concede. The tides turn, however, when the bug malfunctions and Optimus becomes a raging war machine. Hilarity Ensues.
- Similarly, when an aged beauty queen started splashing super models and actresses with an ugly potion, the Space Cats forced her to reveal where she kept the antidote by splashing her with some of the potion. The catch? They actually just splashed her with water, and told her it was the ugly potion. She panicked and didn't check a mirror.
- Subverted in Gargoyles. Demona shoots Elisa with a poisoned dart, blackmailing Goliath's clan into aiding her in exchange for the antidote. Unbeknown to Demona, by a stroke of luck Elisa was not hit by the dart. At the end of the episode, Demona reveals that there was no antidote in the first place and leaves proudly claiming that at least she managed to kill Eliza.
- In Batman: The Brave and the Bold, it turns out that Gorilla Grodd's planetwide evolution device had a single switch that reverses it (so it cured everyone already evolved and de-evolved Grodd to a human). It was essentially a big "THWART PLAN" button
- In an episode of The Simpsons, the villain not only has the antidote, but absentmindedly starts adding it to the food along with the poison until he realizes his mistake.
- The page quote comes from The Tick after he was accidentally sprayed with a plant vitalize that makes plants come alive and attack people. The villain — a plant-man with plans for world domination — indeed has one, for reasons unknown to everyone.
- It's possible that he was keeping it as a fallback in case the plants decided to rebel against him too.
- In the Adventure Time episode "Jake Vs. Me-Mow," a very small feline assassin named Me-Mow with a syringe of poison and a vial of antidote hides inside Jake's nose and poisons him, saying he'll only give him the antidote if he kills Wildberry Princess since Jake exposed Me-Mow's first attempt at doing so himself. Eventually Me-Mow is knocked out of Jake's nose still carrying the antidote, and Finn tries to get it away from him. Me-Mow smashes the vial when he is held down, but after this Jake realizes he can stretch his liver to a great enough size to render the poison into a non-lethal dose. Me-Mow did mention at one point that he was going to leave Jake to die, leaving open the possibility that the antidote was fake anyway.
- Some venomous animals. In some cases, eating the animal (or some part of it) can work, though one shouldn't rely on it. Most places that regularly deal with venomous animals like snakes have some antivenoms on hand just in case anyone gets bitten.
- Large-animal tranquiliser Etorphine is so quickly fatal to humans that vets only handle it with an injector of the antidote right beside them.
- States that have death by lethal injection do this, just in case.
- Hospitals technically have this too. Drugs given in the wrong dose is the same as poison and cases of OD require counter-agent/antidote.