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Evil-Detecting Dog
aka: Evil Detecting Animal

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"[Mouse] was possessed of the uncanny wisdom of beasts for knowing whom to trust."
Harry Dresden, narrator of The Dresden Files, Dead Beat

Unlike humans, animals seem to have an inherent ability to detect a malicious character even if it's not obvious to anyone else. May not apply to pets of a villain, although Right Hand Attack Dogs and Bond-style cats have a surprisingly low sense of loyalty in a pinch.

A character's dog reacting oddly to their presence is often the first sign that character's been replaced by an Evil Twin, or just an ordinary twin. This is not implausible, unless the scent of the replacement for some reason is exactly the same as the replaced person. Heart rate and other things might reasonably be detectable to some animals, too. If the animals know something's coming, sometimes they don't run, they go quiet. In fact, too quiet...

This doesn't always count in a comedic situation; snotty pets frequently hate everybody, and will be nasty to characters who likewise dislike them as well as benign ones who only want to be friends. And this trope is not restricted to dogs — cats and horses are also commonly invoked, amongst other creatures. Nor necessarily animals — some plants have the ability too. When a human character has this power, it's a Gut Feeling.


Note that this is not necessarily completely true in real life. Animals are not necessarily any better at determining whether they will be abused or mistreated by a human than other humans are. They are usually very able to read body language though, as well as pick up on scents and on physiological signals like heart-rate. Real animals can tell if someone is angry, nervous etc: but they can't necessarily tell why.

If the dog is attempting to warn its master or another nearby human character but the warning is dismissed (typically due to annoyance at the dog's repeated barking or other unusual actions), it can be a form of Not Now, Kiddo. Animals can also detect especially good people, if they're a Friend to All Living Things; contrast Enemy to All Living Things.

Compare this trope with Evil-Detecting Baby. Not to be confused with Even the Dog Is Ashamed. If the dog can detect the supernatural, it's because of a Glamour Failure. Contrast Licked by the Dog, where this is used to show the audience a good guy instead of a villain. Then again, sometimes they aren't detecting evil at all, and it's simply that Animals Hate Him. Closely related to Scare the Dog. Sub-trope of Excellent Judge of Character.



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    Anime & Manga 
  • The hentai Alien from the Darkness has Einstein, a ferret who growls and hisses whenever alien-possessed Flair is nearby.
  • Hotarubi from Basilisk has a pet viper that could see through Kisaragi Saemon's disguise. Unfortunately, Hotarubi didn't understand the meaning of her snake biting her lover and just tossed the animal away and sucked the poison out of Saemon's finger by herself!
  • A cat detects Sylvie as a boomer in episode 6 of Bubblegum Crisis.
  • In Delicious in Dungeon, Kuro the kobold has chimeras, soul fusions made with The Dark Arts, as a Berserk Button. Whenever one is near, he snarls and bares his fangs. Which turns out to be early foreshadowing that Izutsumi is a chimera.
  • Fullmetal Alchemist:
    • The Big Bad starting to move around usually coincides with every dog in Central going insane. Not only can animals sense the Homunculi and living Philosopher's Stones, but even the gentle dog Den reacted viciously to one to show the inherent wrongness of what they are. Not only that, when the Big Bad exerts his power enough, he can make every single animal in the city go crazy and bark at the earth, not just the dogs. The Big Bad himself makes animals too afraid to even approach his lair.
    • Special mention should also go to Black Hayate, Riza Hawkeye's dog, who not only can sense the Homunculi but viciously attacked one to save his beloved mistress. Roy Mustang awarded him the honorary rank of Second Lieutenant for his services to their cause.
    • Unfortunately, dogs are only able to sense supernatural evil in FMA; they can't detect mundane evil. Shou Tucker's dog was even a key component when he crossed the Moral Event Horizon.
  • In the third volume for Hetalia: Axis Powers, young Lithuania has a dog with him that starts barking wildly when it sees young Russia. (Who, while not strictly evil, is... very special) Also notable in that Russia was actually a normal kid nation at the time, so the dog was apparently precognitive too.
  • Honoo no Alpen Rose:
    • Jeudi's cockatoo Printemps hates Matilda aka the fake Jeudi on sight and openly attacks her, much to the surprise of everyone else. The "victim" even lampshades the trope via asking if Printemps thinks she's a bad person. He was right.
    • In a milder version, he also dislikes Leon who is far from a bad guy, but is one of Jeudi's suitors who can potentially take her away from her boyfriend Lundi.
  • In JoJo's Bizarre Adventure: Stardust Crusaders, after Polnareff supposedly defeated the user of the Anubis Stand, he takes the user's sword as a keepsake. After he brings it to the hotel the group was staying at, Iggy suddenly starts barking at it, as the others don't know that the sword itself is the real Stand user.
  • The two ghost dogs of Kekkaishi are primarily used to detect other evil spirits or people.
  • Maru-chan is initially terrified of Sawako in Kimi ni Todoke. This is a subversion, however, since Sawako only looks creepy and is actually one of the kindest people you could hope to meet.
  • Guvava, Mylene's empathic pet Tribble-like furball thingie in Macross 7 acts this way when a Protodeviln is around.
  • Gombei from Majokko Meg-chan. Normally a good dog, he react often to evil characters as Chou.
  • The Mysterious Cities of Gold: Long Chow growls and snarls when Ambrosius is around, before the latter is revealed to be Zares.
  • Kiba's dog, Akamaru, from Naruto is able to sense just how strong a chakra is in a person. When he starts whimpering, that means trouble close by.
  • In Saber Rider and the Star Sheriffs there's the Scottish terrier that belonged to Saber Rider's parents. When they were kidnapped and impersonated by Vapor Beings in "The Highlanders", he barked and hissed at them, which weirded Saber out since he was very sweet to them...
  • In episode 15 of Tiger & Bunny Keith Goodman's dog, John, growls at and tries to keep Keith away from the pretty girl on the park bench. The reason being that while Cis looks like a nice lady, she's a Deceptively Human Robot (in appearance if nothing else) and Keith doesn't realise this.
  • Kicchomu in Thriller Restaurant has an uncanny skill in detecting evil spirits and doppelgangers. This is exhibited in episodes 6 and 14.
  • Not evil, but in Tokyo Mew Mew, dogs can sense that Ichigo is a Catgirl even when she's in the form of a human, and start barking at her for no reason. With her Lancer Minto and her boyfriend Masaya both owning dogs, this becomes a problem.
  • In Wild Rose, Tranquilo immediately starts growling when he detects the rogue manbeast's presence and tries to protect Camille from him, getting badly injured in the attempt. In contrast, Tranquilo's immediate acceptance of Kiri shows that he's safe.
  • You Are Being Summoned, Azazel has dogs and cats, and pets, and er, hobos, apparently, in the first episode of the second season. Although not in response to the demons; it's to Akutabe.

    Comic Books 
  • The demons in Chick Tracts are invisible to all the characters... except for Fang, a dog who occasionally barks at them in the background.
  • Black Fury: Total strangers, predatory animals, minions of the bad guy- if there is an ounce of good in them, the titular wild mustang will know.
  • Uncle Sam of the World War I serial "Golden Eyes" and Her Hero "Bill" - he's able to detect that one of Golden Eyes' admirers is a German spy just by looking at him:
    "'Uncle Sam' sallied around the corner of a flower pot, took one long stare and launched himself through the Spring air, just at the terrible minute that the man with the bristling blond hair tried to take her in his arms. And over his heart, under his thrown back coat, through the white mane of 'Uncle Sam,' who was howling at this throat, an Iron Cross shone out!"
  • The Flash: When "Impulse" Bart Allen was replaced by his Evil Twin Inertia, the only character to realize was Bart's dog, but Inertia was able to get around that with treats. And by not thinking any evil thoughts around the dog.
  • In the mid-90s RoboCop Versus The Terminator comic book, one of the humans remarks on the fact that a dog acts friendly, rather than hostile, to Robocop, proving to the human that said character couldn't be a Terminator.
  • Arwyn's dog Kreeg in Sojourn has this ability. It saves Arwyn and her allies more than once.
  • Wookiees are explicitly sentient, but since they're hairy and unintelligible, unimaginative writers of books and comics alike love to make them as animalistic as possible. This is taken to a new height (or low) in "The Phantom Affair" arc of X-Wing Rogue Squadron — a woman who has a Wookiee hanging around due to a life-debt doesn't understand him, and he doesn't communicate with her at all, he's just a bodyguard — who starts growling and provoking "Groznik senses something!" before they get attacked.
  • Superman:
    • Batman tried to bring up this trope in The Supergirl from Krypton, noting how Krypto hated Kara Zor-El, Superman's cousin who had just arrived on Earth. It was ultimately subverted as Superman pointed out that 1) It was Krypto's job to protect the Fortress of Solitude, and 2) He hated everybody.
    • In Superman: Doomed, Krypto growled at Superman after he had been infected with Doomsday's cells and was slowly turning into a copy of Doomsday. Superman even commented that it was something out of a horror movie.
    • All-Star Superman: Subverted. Krypto's spooked by the new farmhands, but they are actually Superman's descendants, who came from the future to protect the past from the Chronovore.
    • In The Unknown Supergirl, villainess Lesla-Lar impersonates Supergirl, and neither her cousin nor her adoptive parents notice that Kara has been replaced by an impostor. Nonetheless, Krypto the Superdog sees through her act as soon as he meets her due to "Supergirl"'s different scent, mannerisms and behavior.
  • In Supreme Power, his foster parents give the alien baby Hyperion (a modern version of Superman) a puppy for his first birthday. It immediately senses, that he is not human, and tries to attack him. He promptly (and instinctively) annihilates it with his heat vision.
  • In Zombies: A Record of the Year of Infection the main character writing an Apocalyptic Log notes that dogs go nuts at the presence of zombies, including frequently attacking them. Furthermore his dog seems to mistrust the people when he reaches the supposed "safe haven" of Churchill in Manitoba Canada. Since there is No Ending, exactly what happened is left open to interpretation, but one interpretation is that the highly isolated and suspicious locals killed the main character.
  • Snowy, Tintin's dog, often has people figured out as evil on instinct before Tintin has proof.
  • In the Mickey Mouse Comic Universe this is the most reliable way to identify Miklos the Grey Mouse whenever he's disguised as Mickey: while Miklos is such a Master of Disguise anyone else can't tell them apart and, if they can, won't be sure, Pluto will unfailingly growl and snarl at Miklos, remembering how in his first appearance the Grey Mouse kidnapped and beat him, while also being able to recognize Mickey with a sniff.
  • Wonder Woman Vol 1: Diana's horse Serge has a sort of sixth sense that allows him to rescue a child from a villain that attempted to run the kid over before Diana realized who was driving the car or their intentions.
  • In Spirou and Fantasio, the Marsupilami is able to detect evil (and good) characters before any evidence is given. Given that he's also very strong and has a short temper, this means he occasionally flies into a rage and attacks what looks like perfectly innocent strangers to the other characters.

    Comic Strips 

    Fan Works 
  • The cats are used for this in Aeon Entelechy Evangelion, as they are sensitive to anything abnormal, a quality shared only by human infants, and thus are also used in CATEYES security systems. This also seems to be common knowledge since Shinji notes their absence in the dome where Rei lives.
  • In Blue Sky, even though Wheatley is not really evil at that point, Duke can still detect that he isn't human.
  • The Bolt Chronicles: Bolt is normally very disapproving of Penny’s boyfriends, expressing this through dirty looks and grumbling — though for good reason, as she usually chooses unwisely. She sometimes ignores the dog’s instinctual character sense, always to her detriment.
  • The Bridge:
    • One of the first signs that Enjin has caught up to the sirens and Monster X is all the animals, from forest creatures to pets, start fleeing the area as fast as they can and leave the forest dead silent. This also happens when Mizu is rapidly moving across town at night, numerous pets sensing it passing by and being terrified.
    • Dogs can tell Jeog is evil and drive her off with their barking, as she cannot stand the sound of barking.
  • Discussed in Calvin and Hobbes: The Series:
    Calvin: Did you hear the theory that when a dog barks at nothing, it's barking at a ghost or a spirit?
    Hobbes: Nah, that's a load of hooey.
  • In Candy For Your Thoughts?, Duncan gets a Morality Pet in the form of a dog used in one of the challenges. Despite being super-friendly, "Mohawk" growls at Heather and Alejandro when Duncan is eavesdropping on them. It would have saved Duncan a lot of grief if he had paid attention to this, since the pair knew Duncan was watching and were spouting a bunch of lies to mislead him.
  • In The Dilgar War dogs are the only thing that can locate the Spectre, Dilgar special forces equipped with cloaking suits.
  • In Little Black Death Note Professor Lupin is the "Evil Detecting Werewolf". He freaks out around Hondo Marukai because he "reeks of death".
  • The Many Dates of Danny Fenton, a Danny Phantom fanfic:
    • in this case, but Salem, having been a warlock, can sense Danny's innate supernatural abilities.
    • While Katie isn't evil, her presence causes Buttons to be terrified of her.
  • In Mega Man Reawakened, Rush sees right through Snake Man's ploy.
  • In the Sonic the Hedgehog fanfic The Memory, a little boy named Christian can see Cute Ghost Girl Maria and so can his dog. Most other people can't.
  • Invoked in Nutss Ghost Story when Murphy tries to convince Molly that Shepard's alright by reminding her that Mouse hasn't had his usual reaction to Outsiders around Shep.
  • Pokémon Reset Bloodlines:
    • In a sidestory starring Gym Leader Luana, her Pokemon were shown scowling at the man who would be Travis's father (and the father of a lot of others, up to and including Ash Ketchum) the moment he appeared. Given this very same man was shown in the later Holiday Special 2017 to be quite The Sociopath, they were right to distrust him.
    • Misty's Psyduck is also this, quickly picking up that a trainer they casually ran into was up to no good with Misty (heavily impled to be a Date-Rapist), and punches him out before he can do anything to her.
  • Rise from Darkness: A man's dog sniffs Samus and can instantly tells that there's something weird about her.
  • Lucille Harewood's dog in the Star Trek (2009) fanfic Safe and Sound was specially trained for this purpose because of what her father did for a living. This is how her mother figures out that Dr. Korby isn't as trustworthy as he seems...
  • Mika the cat has yet to meet any official villains in Yesterday Upon The Stair, but her response to the “Hero” Endeavor approaching Todoroki is a protective hissy fit.
  • Garo from Their Bond is a wolfos who is very protective of his owner and "beta-omega" Zelda. He distrusts most around her and is generally skilled at telling bad intentioned people, but he's not always right (such as with his thing against Zelda's girlfriend Impa). His distrust of Link serves as foreshadowing. It initially seems like he hates Link because Link is a dominant "alpha" with wolf-like characteristics, but it's actually because Link is a troubled and potentially dangerous Addled Addict.
  • White Sheep (RWBY): Zwei, as the dog of a huntsman, has his Aura unlocked and is very well trained. Therefore when he sees Jaune, who is secretly half-Grimm, he immediately goes for his face. Jaune spends the next day fighting to keep him from gnawing various bits of him. That being said, it's later implied that Yang's father specifically set Zwei on Jaune because Yang and Jaune are dating.
  • Bethany Hawke uses her brother's mabari, Dane, in this way in Beyond Heroes: Of Sunshine and Red Lyrium. The group needs to know for sure whether or not the people they're seeing are real, but they all have such an emotional response to the situation that they can't trust their own judgment; so she employs the dog, whose breed is renowned in the setting for its extremely high intelligence and good judge of character, to make the call.

    Films — Animation 
  • Done subtly in Coco. Miguel's Canine Companion Dante travels with him in the Land of the Dead as he searches for Ernesto de la Cruz, whom he believes is his ancestor who can give him his blessing to become a musician. Yet during their time, Dante seems to keep Miguel from just going directly to Ernesto and instead keeps him around Hector. It turns out Dante is an alebrije who is trying to bring Miguel closer to Hector, his real great-great-grandfather; while keeping him away from Ernesto, who is a fraud and Hector's murderer.
  • Epic: Ozzie growls at the bat call, which is being sung by Mandrake.
  • In Hoodwinked!, Twitchy, funnily enough, is the only one who appears suspicious of Boingo while everyone else doesn't give a second thought about trusting him.
  • In Hotel Transylvania 3: Summer Vacation, Tinkles angrily barks nonstop at the presence of Abraham Van Helsing.
  • The Little Mermaid: Eric's dog Max absolutely loves Ariel even before he sees she's responsible for saving his master's life in the storm. However, he hates "Vanessa" (Ursula's Human Disguise) and growls at her, giving her a literal Kick the Dog moment just to shut him up.
  • In the obscure Spanish animated film Nocturna, all the cats in the Cat Shepherd's pack start to go and yowl at a wall. The Big Bad of the film, the Shadow, is then revealed, slipping out of the, um, shadows.
  • In Princess Mononoke, San and her wolf companion find hundreds of mice scurrying away from the direction where humans are using boar skins to masquerade themselves to find the Forest Spirit. Apparently they're so terrifying that they willingly scurry over a full grown woman and a giant wolf to get away.
  • Snow White and the Seven Dwarfs: All the animals instantly realize the "old peddler woman" (the Wicked Stepmother in disguise) is evil even while Snow White herself is Genre Blind; they attack her when she first attempts to give Snow the poisoned apple, but Snow shoos them away and at the hag's request takes her inside the cottage. With that they head to the mine of the dwarfs, who are similarly puzzled by their aggressive behavior until Sleepy theorizes that they're trying to enlist their help to save Snow.
  • The Jinnouchi family dog in Summer Wars is so good at detecting evil that it can sense a satellite changing course in orbit. He's pretty skilled at detecting good as well, if his reactions towards a certain Jerk with a Heart of Gold are anything to go by.

    Films — Live-Action 
  • The cat who's taken up residence in Marnie's house in 100 Feet frequently detects Mike's presence before he becomes visible.
  • Simultaneously referenced and used straight in Ace Ventura: Pet Detective. When Ace is making the acquaintance of Roger's dog on the crime scene, the dog barks at Lois Einhorn when she walks in:
    Ace: So, animals can sense evil.
    • He later learns that Lois is the killer — and, as it turns out, a man. And if the dog witnessed the murder, his reaction to Lois, someone who harmed his master, is perfectly natural.
  • Alien:
    • In Alien (1979), the cat is able to detect the titular creature, though no one apart from Ripley seems to be aware of this.
      • Brett does notice that the cat is hissing at something, but by the time he turns around to see what's bothering Jones, it's really too late.
    • In Aliens, during the opening dream sequence, Ripley's cat senses the Chest Burster inside her and starts to hiss.
    • In Alien³, a dog barks incessantly at a crawling facehugger, which then infects the dog.
    • Alien 40th Anniversary Shorts. In "Specimen", a Doberman Pinscher trained to detect contaminated samples detects the facehugger and barks away accordingly, but the humans decide to deal with it in the morning. Fortunately the Doberman is revealed to be a synthetic animal who can hold its own against the alien.
  • Shortly after he has been attacked by a werewolf in An American Werewolf in London, all sorts of animals start hissing and growling at David. The only exception is wolves. They don't seem to mind him too much.
  • In Annie, Sandy reacts to Annie's hired "real parents" with aggression and fear.
  • In Arachnophobia, both a cat and a dog can sense that the General is, if not technically evil, than certainly not to be messed with. A crow does not realize this in time.
  • Bad Moon arguably revolves around the trope, being from the point of view of the dog as he realizes the uncle is a werewolf and attempts to defend the family from him. Unfortunately, he's not able to warn the family and him attacking the werewolf while in human form gets him taken away for supposed aggressive behavior, but the boy frees him in time to race home and kill the werewolf himself.
  • Bird Box: Birds can sense when the creatures are around and chirp wildly when they're near. Malorie figures this out when her group have to raid a supermarket and she comes across a trio of parakeets that were left behind. Not shortly after the group have their first encounter with one of the unhinged with the birds reacting to his evil intent. She hangs on to them for the remainder of the movie.
  • In Blackenstein, a dog whines and barks at the approach of the monstrous Eddie. Eddie kills the dog, and the householders go to investigate why the dog has gone silent. Bad move.
  • In Cello, the family's pet dog, Sunny, barks loudly when it is near the titular musical instrument.
  • In Cloverfield, when the trio head into the subway system to hide, they find dozens of rats scurrying away from the rear end of a darkened tunnel. One of the characters, Marlene, realizes they have to get away from the area the rats were running away from. Minutes later a giant parasite attacks the group and injures Marlene, who dies a nasty death from the infected bite.
  • The Perron's dog Sadie in The Conjuring refuses to enter the house, sensing the evil force within. Unfortunately, this doesn't save her.
  • Daredevil: From the Director's Cut is a scene at an airport where Bullseye is going through security. He briefly glares at one of the security dogs, which whimpers in fear.
  • Dogs bark, horses rear, and cats snarl at the mysterious woman in 1955's Cult of the Cobra, because they can tell she's a venomous snake in human form.
  • The dog at the end of Dead Birds sees William as the skinless, eyeless abomination that attacked the group at the beginning, and starts to bark and then chase him.
  • Van Helsing in Dracula (1979) confirms his suspicions about his late daughter's vampirism by investigating her resting place with a horse. When the horse comes by her grave, it starts stomping the ground with its hoof, and then runs away in terror. Van Helsing and Dr. Seward then start digging.
  • In Extremely Wicked, Shockingly Evil, and Vile, a dog begins barking at Ted Bundy with no provocation, obviously able to detect he's a monster long before most of the people who know him can. This is based on the account of true crime author Ann Rule, who knew Bundy in real life before he was first suspected of being a serial killer. In The Stranger Beside Me, she states that everyone found Bundy pleasant to be around save her dog, who loathed him.
  • In Fair Game, Jessica's dog Kyla snarls anytime the hunters are in the vicinity or approaching, even if they cannot be seen or heard at the time.
  • The Field Guide to Evil: In "A Nocturnal Breath", Xaver's dog Wachter is able to detect the evil drude when it is possessing a mouse. Wachter goes mad, barking wildly, and Xaver has to drag him off before he tries to eat it.
  • Played with in The Fly II: Guard dogs are sent after Martinfly, but they fearfully stop in their tracks at the sight of the monster. However, Martinfly retains the mind and morals of Martin Brundle, who likes dogs and knows they don't deserve to be victims of his Roaring Rampage of Revenge, and thus he literally pets one of them before moving on.
  • In Plot A of Frenemies, Murray (Jake's dog) was the first to know about Julianne's true intentions and acts very aggressive towards her (growling at her, making her sit on paint, trying to flush a lover letter she wrote for Jake, etc.). However, Jake remains oblivious to all of this and thinks Murray is just acting up.
  • From Beyond the Grave: When Warren arrives home with the invisible elemntal on his shoulder in "The Elemental", his dog whines and refuses to come near him. He later runs away. When Madame Orloff arrives to perform the exorcism, one of the first questions she asks is if their dog as run away, and goes on to explain that animals and children can sense elementals, and sometimes even see them.
  • Good Burger: Dexter and Ed come across a hungry stray dog. Ed gives a hungry dog a Mondo Burger patty, but the dog won't eat it for some reason. So Ed gives the dog a Good Burger patty instead and the dog immediately eats it. This begins to make Dexter and Ed suspicious about Mondo Burger.
  • In The Gravedancers, Allison's cat senses that something is seriously wrong with Harris as soon as he returns from the cemetery. It takes one sniff, hisses and flees.
  • Lester the family dog barks at Michael Myers hiding behind the bushes in Halloween1978.
  • In The Hand, Jon's cat senses the presence of the Evil Hand in the cabin long before Jon does. It investigates, is attacked and flees; never to be seen again in the film.
  • In the film version of Hannibal, Hannibal Lecter breaks into Agent Krendler's house and his dog is initially hostile, but Hannibal actually makes the dog cower in the corner while he pokes around.
  • In Hereditary, the family dog has a moment where it enters Peter's room and starts to bark because it can sense the spirit of Charlie.
  • The female character's pet dog in The Hole (2009) runs away when the human character's are investigating the, uh, hole and she states the dog doesn't like it. The dog also freaks out when something tries to drown the little brother.
  • In Hook, Nana the dog senses that the titular Captain is about to invade the Darling home and starts barking.
  • I Married A Monster From Outer Space. The heroine wonders why her husband (having been possessed by an alien) no longer likes the dog she bought him as a present, and vice versa. He eventually kills it and tells her that it died in an accident. In the climax, some German Shepherds are more effective than bullets in taking on the aliens.
  • In The Film of the Book of Interview with the Vampire, Louis is attempting (clumsily) to seduce and then kill an elderly woman. Her pet poodles, however, won't stop barking at him, evidently sensing the ill intentions of the vampire - and the noise drives him to kill them instead.
  • In In the Line of Fire, Pam's dog growls aggressively at "James Carney", who is really would-be Presidential assassin Mitch Leary, and who kills Pam and her roommate.
  • In Jack Brooks: Monster Slayer, Crowley's dog detects the evil early in the movie, but is unwilling to abandon his owner.
  • In Jeepers Creepers 2, the farmer's dog is the first one to notice that there's something off with one of the scarecrows...
  • Wolf in The Journey of Natty Gann reliably warns Natty of all kinds of impending trouble.
  • Owen's Velociraptor pack from Jurassic World really dislike Vic Hoskins, a Blood Knight who wants to use the dinosaurs for modern warfare. One example is shown when they have a snarling fit whenever Hoskins arrives at their holding pens. Delta especially seems to have it out for him, and she is the one to slaughter him near the end of the movie.
  • Downplayed in Knives Out. The dogs don't so much detect evil, but they only bark at those they deem strangers. Lampshaded by Blanc, who notes that he's always felt that dogs are excellent judges of character.The barking becomes a Chekhov's Gun in witness stories on the night Harlan died, signifying that there was a stranger on the property. They end up playing the trope straight though as Ransom — the culprit — is the only member out of the Thrombey family and their household staff that dogs bark at, having been estranged from the family for some years and is shown to be a jerk in his Establishing Character Moment.
  • The Lord of the Rings:
    • The horses in The Return of the King have every reason to be scared of the mountain where the Dead dwell. For once, the Humans understand the reasons for their fear. Elves, however, don't. The Dead aren't really evil, and end up being of great help to our heroes... but they're still pretty darn scary.
    • There's also a scene in The Fellowship of the Ring where a dog barks furiously at a Ringwraith, but does so while backing up. Eventually, it retreats with a whimper.
  • In The Lost Boys, Nanook growls at Michael, after he drank some of the blood-in-a-wine-bottle while hanging out with the vampire hoodlums.
  • The president's dog in Mars Attacks! barks at the Martians on the television.
  • Milo does this twice in The Mask. First, he detected that The Mask was evil. Second, he detected that his owner was kidnapped when he saw Dorian's goons invade the apartment for the stolen bank money and chased after their car to rescue Stanley.
  • In The Monster Maker, Ace seems to know that Dr. Markhoff is up to no good when he enters the lab to release the Killer Gorilla to murder Maxine, and starts growling at him as soon as he approaches the cage. Markoff eventually banishes him from the room.
  • In Ms. 45, the landlady's dog, who knows protagonist Thana well as she used to walk it, catches on to her increasingly strange behavior (in particular her disposing of the body of a rapist piece by piece) quickly. Initially Thana manages to placate the dog, but eventually she asks to walk it again and takes it out to the riverside, ties it up, and takes out her pistol... the final scene shows it returning to its master's apartment, having freed itself sometime after Thana spared it offscreen.
  • Used a lot in the 1944 film The Mummy's Ghost, in which dogs barking the alarm or biting at his ankles actually pose a greater obstacle to the mummy's comings and goings than anything the human characters do.
  • Animal is the only Muppet to notice Kermit has been replaced by Constantine in Muppets Most Wanted.
  • In Near Dark, the earliest sign that love interest Mae is not all she seems is that the hero's horse goes nuts when he tries to show him to her.
  • In Please Stand By, Pete growls at a couple right before they rob Wendy.
  • In the short film adaptation of Stephen King's The Road Virus Goes North, the protagonist is dumbfounded as to why dogs bark madly at him wherever he goes. They're actually disturbed by the cursed picture he's got in his car. When the titular Road Virus himself first appears, the dog falls instantly silent except for a few terrified whimpers.
  • Also used in the Stephen King miniseries Rose Red, where an otherwise nice dog bites the powerful, autistic psychic Annie. While Annie is not exactly evil, she does retaliate by causing rocks to fall from the sky and crush the house of the people who own the dog, so the dog's attitude was arguably justified.
  • One of the freakier aspects of The Omen (1976) is how most animals - with the exception of one dog - react when in the presence of little Damien, the son of Satan himself. One memorable scene has Damien and his mother on safari, and their jeep being swarmed by furious baboons.
  • Outpost: Rise of the Spetsnaz. After being thrown into a cell in an underground Nazi medical experimentation lab, the Russians note that despite the smell of decay there's no sign of rats or their droppings. "You know you're in trouble when the rats have abandoned ship."
  • In both The Parent Trap (1961) and The Parent Trap (1998), the dog owned by one of the twins reacts with barking and growling when the other twin, pretending to be her sister, tries to greet her/him. (In this case, the twin isn't evil - the dog just knows she isn't who she's claiming to be.) In the latter film, the dog also has an evil-detecting reaction to the twins' father's new girlfriend.
  • Averted in Perfume. Thanks to the villain's complete lack of scent, he steps right over a sleeping dog as he's sneaking up to Laura's bedroom, without it sounding the alarm.
  • In Poltergeist, the family dog starts barking at the walls after the titular ghosts arrive.
  • Kelly's dog Ginger in Race with the Devil is the first to notice the cultists. It later gets hanged from the RV's door.
  • Reign of Fire. A tethered hawk is used to detect the approach of dragons, though it proves less effective at detecting the approach of a convoy of gung-ho American dragonslayers.
  • In Relative Fear, Earl's dog barks at Adam every time he's in the room. It turns out he's really reacting to the presence of Garrett Madison in the attic.
  • During his villain monologue Richard III complains that dogs bark at him whenever he's nearby. Well what does he expect when he's about to drive a tank through the wall?
  • The dog-like alien creature adopted by Riddick is disturbed at the approach of rain. Riddick tells it there's nothing to worry about, goes to pet it... then realises from its tense body that he'd better start worrying.
  • In M. Night Shyamalan's Signs, the dogs smell big-time alien and bark and bluster accordingly.
  • In Sleepwalkers, the villains morph into somewhat feline creatures, but are hated by actual cats.
  • Super 8: All the dogs in the area run away to other towns because they can tell there's a monster running around.
  • Terminator: Ever since SkyNet churned out Terminator robots disguised as humans, the Resistance found a way to counter this by training "sniffer" dogs to smell human hands, and they can be further trained to hear the sound of Terminator servos moving, which is too low to be detected by humans.
    • Dogs are used to detect Terminator robots in the Robot War in The Terminator. In the 1984 scenes, a pet dog also barks madly at the T-800 as it walks up to Sarah Ann Connor's house to murder her. Later on, Sarah and Kyle are alerted to the T-800's presence by a German Shepherd barking loudly.
    • Terminator 2: Judgment Day: The dog does bark like crazy off-screen at the malevolent T-1000 while it's impersonating John's foster mother. In a Deleted Scene, this dog is killed by T-1000, eventually. However, the film includes a scene where a dog does not react to the T-800. The filmmakers admit this is a plot hole, but felt it was better to not confuse the audiences.
    • In Terminator: Dark Fate, a Terminator who lived for years among humans and even adopted a human family also has a pet dog who is entirely comfortable with his presence. As per this trope, this is a sign that he is no longer out to Kill All Humans because he has learnt human traits like empathy. The trope is played straight with the Rev-9 Terminator who turns up at his target's house posing as a friend, and the dog immediately starts barking at him.
  • The Thing (1982): Although they don't react to the Thing immediately, the dogs eventually rouse themselves and start growling and snarling at the newcomer, despite its (initially) normal appearance.
  • Tremors: Two instances of this happen, first with a farmer's flock of sheep, and second with a pair of horses the protagonists happen to be riding on even though there isn't any danger visible. The farmer doesn't realize until it's too late that something's wrong, but one of the protagonists figures out the horses "got wind of something they don't like". Sure enough, it's a reliable sign that the movie's Sand Worm monsters are about to attack.
  • In Vampires vs. Zombies, Bob's dog growls at the gas station attendant when he comes back into the station. It is later revealed that he had been bitten by Carmilla while outside and turned into a vampire.
  • The Whisperer in Darkness: In the teaser for the H. P. Lovecraft Historical Society's adaptation, a scholar listens to a wax cylinder recording of a man spouting occult ravings while a cat sits impassively nearby. Suddenly ANOTHER voice cuts in on the recording, and the cat startles and hisses. In the movie itself, a colleague hurriedly switches off the phonograph when he's been listening to the wax cylinder recording of the cultist ceremony throughout the night.
  • More like "Evil Detecting Horses", in The Wolfman (2010). Also evil detecting bear and evil detecting deer. Ironically averted by the single dog (it always growls at Lawrence, well before he is infected, while it is completely oblivious to the original werewolf because he is its owner).
  • Wolves: After Cayden starts work at the Tollerman farm, his voiceover muses that "Even if the Tollermans didn't know what I was, the animals sure did," over an aerial view of a flock of sheep running away as he gets close with their feed.
  • In Zoltan, Hound of Dracula, Zoltan was originally this: turned by Dracula in vengeance after it protected a woman from him. The Drake's dog Samson is also this; able to sense the presence of Zoltan and Veidt.

  • Inverted in The Belgariad, birds seem to instinctively know (and love) Polgara, even if they've never met her. The Emperor's bird even chews him out for not recognizing her.
  • In Samuel Taylor Coleridge's "Christabel", one of the first signs something is not right with Lady Geraldine is the untypical reaction of the dog: "The mastiff old did not awake,/ Yet she an angry moan did make!/ And what can ail the mastiff bitch?/ Never till now she uttered yell/ Beneath the eye of Christabel."
  • In Joseph Sheridan Le Fanu's Carmilla, the mountebank's dog will not cross the drawbridge into the courtyard of the schloss, and howls continually while the mountebank converses with Laura and Carmilla. For added irony, the mountebank is eager to sell his vampire-repellent charms, but scolds his dog for howling. Possibly a nod to "Christabel".
  • The Cat in the Stacks Mysteries: Both cats and dogs in this series and its spinoff, Southern Ladies Mysteries.
    • Charlie Harris's Maine Coon cat Diesel has a knack for telling nice people from nasty ones. People he dislikes include one crook in book 2 and two Asshole Victims in book 3, and in book 7, he backs away from Oscar Reilly when they first meet, even before the man proves to be a total jerkwad, showing that Diesel's instincts are spot on.
    • In Ladies #4, the Ducote sisters' dog Peanut reacts with hostility to the greedy and thoroughly unpleasant Nathan Gamble.
  • In the The Cat Who novels, Qwill's hyper-intelligent Siamese cat Koko has shades of this. It's particularly showcased in The Cat Who Saw Red; Qwill is given an art piece by the man who married Joy, Qwill's first love, and he knows he hates the man, but he has no real reason apart from jealousy. Koko circles the piece of pottery and then hisses at it, prompting Qwill to decide, "We can't both be wrong." The red glazing on the pottery was created by its artist putting Joy's body into the kiln after he murdered her.
  • Wolf from The Chronicles of Ancient Darkness can smell demons and see spirits.
  • In Robert E. Howard's Conan the Barbarian story "The Scarlet Citadel", Pelias scares away a giant snake by letting it look at him. Conan is very afraid that it was an evil-detecting snake.
    An icy trickle disturbed Conan's spine, and he wondered if, after all, Pelias were a man, or merely another demon of the pits in a mask of humanity.
  • In Coraline, the mice belonging to the crazy old man upstairs give the eponymous protagonist a message by proxy: "Don't go through the door." They're absolutely right — said door leads to the fantastical Other World, which contains magic toys, delicious food, and a life-sucking beldam who just loves in, loves to steal their souls.
  • Susan Cooper used this more than once in The Dark Is Rising series.
    • In Over Sea, Under Stone and Greenwitch, Captain Toms' dog Rufus fears and dislikes the minions of the Dark.
    • In The Grey King, Bran's dog Cafall guides Will onto the Old Way, and later attacks one of the foxes that serve the Grey King.
  • Discworld:
    • In the Discworld series, one of the only creatures capable of seeing Death when he's not trying to be visible are cats. Strangely, Death actually likes cats, and in fact one of the things he hates most of all are people who mistreat cats. Although the Discworld's Death isn't evil. This is more an example of Cats Are Magic.
    • In Sourcery, the Patrician's dog, Wuffles, growls at the sourcerer's staff.
    • In Wyrd Sisters this is subverted; Granny says that dogs are most concerned with how their masters treat them, not others, so an evil man can end up with a devoted dog so long as he takes good care of it. She's also using the dog as a metaphor for the kingdom of Lancre which has recently awakened to the fact that Felmet, the usurper, doesn't care about it the same way the old king did.
  • Bailey in A Dog's Purpose detects something off about the Enfant Terrible Todd not soon after meeting him. Unfortunately, he can't figure out what, even after Todd tries to kill him, until years later.
  • In Bram Stoker's Dracula dogs and horses are frightened by the Count's presence but he can control wolves.
    • When he goes out to meet Jonathan Harker, the horses pulling Harker's cart panic, though the jet-black beasts pulling his own carriage obey him without hesitation.
    • At a funeral for one of Dracula's victims, a dog belonging to one of the guests refuses to go near the grave.
    • A wolf at a zoo in England snarls and lunges at the bars of his cage when the Count comes near, but calms down when he gets closer. And later escapes and breaks through Lucy's garlic-protected window.
  • In one book of Mercedes Lackey's Dragon Jousters, the tamed dragons - who are established as being as smart as bright dogs — hiss and go into threat displays whenever they see a Magi. This might just be because they watch their riders' body language and know that the riders hate the Magi.
  • The Dresden Files:
    • In book 6, Blood Rites, Harry comes into the possession of a puppy, who he names Mouse; during it, he growls at people that Harry later learns are evil. Mouse grows up to be a very, very large dog, and is explicitly identified as a Temple Dog: the descendant of a spiritual creature who bred with a normal dog, with a couple of supernatural abilities, mostly of the detection or warning variety. He's also way smarter then a normal dog, occasionally looking like he understands English to a degree. In Changes, we find out that he can. Mouse's breed is in such high regard that Ancient Mai, one of the most powerful and nastiest wizards, will accept its judgment and testimony without second thought. Also Nicomedeus, a 2,000 year old demon-possessed arch-villain and leader of a bunch of other demon-possessed people, is apparently afraid of Mouse.
    • Harry's first pet, a large housecat named Mister, gets along fine with the supernatural... so long as it's not an immediate threat, or else interrupting his dinner.
      • Funnily enough, while Mister is big, he's tiny compared to Mouse, yet he constantly bosses Mouse around. Anyone who's ever owned a large dog and a smallish cat know that's totally Truth in Television, especially if the cat was able to establish its dominance while the dog was still a puppy.
    • In Small Favor, the Pacific white-sided dolphins at Shedd Aquarium start chittering loudly to alert Harry that he's about to be ambushed. When one of the Blackened Denarii falls into their tank, the cetaceans scatter, swimming away from the cursed coin as if they recognize that it's a threat.
  • In Emergence, Terry (a macaw) takes an immediate and intense dislike to Rollo, an opinion later events show to be entirely justified.
  • A variant in Everworld: for whatever reason, horses (including talking ones) will not allow a witch to ride them. Witches don't seem to be Always Chaotic Evil, but this trope certainly applies to Senna.
  • In the Fairy Oak series:
    • Nibbler often finds himself as the victim of a transformation spell because of his habit of confronting emisaries of the Enemy. On a less serious note, he heavily dislikes Adelaide Spleenworth, one of the few villagers who is truly egotistic.
    • Barolo starts barking and growling at the four men that unexpectedly arrive to the Poppy's house. Sure enough, they are all part of the army of the Enemy.
  • Family Skeleton Mysteries: Sid the ambulatory (and friendly) skeleton has encountered a few, who sense there's something inherently wrong about him.
  • Subverted in a Father Brown short story. In the beginning, a young man is telling the story of a murder case where, he claims, his dog told him when the murder took place by howling, and who the murderer was by barking at him. Father Brown thinks about the story for a week, and then tells his own interpretation to the young man. This interpretation is based on having the dog acting entirely as an animal, it points to another person as murderer, and it is of course the correct one.
  • In Firebird (Lackey), all the animals around the palace hate Tsar Ivan and Ilya's brothers, calling them the Monsters.
  • Forest Kingdom: At one point in book 2 (Blood and Honor), Jordan finds a bloodhound in his quarters, who starts growling when a messenger from Prince Lewis shows up. Jordan remembers the old stories about dogs being able to detect evil, and is willing to trust the animal's instincts.
  • Played with in Caitlin Davies' The Ghost of Lily Painter. Jojo the dog reacts with anger or fear to Lily's presence, but aside from some occasional poltergeist-style activities, Lily turns out to be benign.
  • Gavin de Becker's book The Gift of Fear claims that dogs will growl at untrustworthy people because their owners will detect the malicious intent and broadcast their discomfort with subconscious cues.
  • In Andre Norton's short story "All Cats Are Gray", Bat the cat alerts her owner Steena to the presence of a hostile, invisible alien lurking on the ship she's trying to salvage, allowing her to shoot it before it can attack. Steena later explains that the alien was using Chameleon Camouflage. Since Bat is a colorblind cat, this results in a Glamour Failure, allowing him to see it normally. The twist comes from the fact that Steena is also colorblind. She couldn't see the creature as clearly, but Bat's reaction was more than enough to compensate. A rare example of someone actually listening to the Evil Detecting Cat.
  • Goosebumps:
    • The protagonists' pet dog in the first book, Welcome to Dead House, barks around everyone in town since it can tell that they are actually dead. Eventually, the dead people get fed up with it and actually kill the dog as a result.
    • Likewise in Ghost Beach, where the old man's dog ultimately detects that the kids' aunt and uncle are ghosts, too.
  • In the Harry Potter novels, the cat-like creatures called Kneazles explicitly have this ability. Crookshanks, Hermione's cat in Harry Potter and the Prisoner of Azkaban, is part-Kneazle. He immediately takes a disliking to Scabbers because he knows that Scabbers is actually Peter Pettigrew in his Animagus form. Conversely, on the other hand, he trusts Sirius Black's dog form enough that Sirius is able to get him to acquire Neville's list of Gryffindor common room passwords. When Ron gets a new owl, he holds Pigwidgeon in front of Crookshanks to test his reaction; Crookshanks's lack of interest is good enough for Ron.
    • Also potentially of note in Harry Potter and the Chamber of Secrets is that spiders are afraid of basilisks, because they have eight eyes pointing in every direction, and no eyelids. If there's a basilisk anywhere near them, they can't help but look directly at it and be killed.
    • Fantastic Beasts and Where to Find Them describes Crups, wizard-bred dogs that resemble Jack Russell Terriers except for their forked tails, which are hypersensitive to Muggles.
  • Subverted in In the Seasons of Rains by Ellen Steiber. The protagonist hears one of his cats (a female) screaming in terror, but when he goes to investigate finds his way blocked by his two male cats who scratch and bite him. When he returns to his bed, the female cat is sitting apparently unharmed on his bed. The man is being stalked by a Horny Devil (suggested to be the Biblical demoness Lilith) who can shapeshift into cats or owls.
  • In Little Girl Lost when young Tina Miller falls into the fourth dimension, the family collie Mack wastes little time barking up a storm and running right into rescue her when they let him inside the apartment.
  • The Lord of the Rings:
    • Animals react strongly to the presence of the Ringwraiths. In the books, the wraiths' horses (and later, the vaguely pterodactyl-like mounts that fans have dubbed "fell beasts") are an exception, due to being trained from birth to tolerate them. The first movie features spiders, wetas, and other creepy-crawlies moving to get away from the wraiths, although the horses look quite evil.
      • A dog-specific example would be Farmer Maggot's dogs, who really didn't like the Ringwraith who came visiting; its very presence sends them off with a yelp.
      • The fell beasts themse;ves have this effect, with none of the other animals (even the cavalry of their own allies) wanting anything to do with them. After one of them is killed at the Battle of the Pelennor Fields, it's mentioned that its carcass doesn't decompose properly and leaves a stain in the earth, as if even the worms don't want anything to do with it.
    • Much like the example under film, animals are deeply unnerved by the Dead Men of Dunharrow. The horses of the Rohirrim shy away from the path leading for the Dimholt, and Arod (the horse loaned to Legolas) balks when Aragorn's company later attempts to take the Paths of the Dead. It takes Legolas' direct encouragement before he is willing to enter the mountain, and it's also state that the only reason the horses of the Dúnedain and Sons of Elrond bear the journey is because of the love they have for their masters.
  • Pretty much universally true in H. P. Lovecraft's works. (Below are just a few examples.) On the other hand, humans have almost the same ability, as Lovecraft's narrators and characters constantly go on about how eldritch and wrong the things they encounter feel (or seem or look or smell or sound), even if they can't explain why or don't even clearly see anything.
    • In The Dunwich Horror, the weird (and unnatural) Wilbur Whateley carries a gun for self-defense against other villager's dogs. A dog still gets him in the end. In a library, of all places. And just to show just how much dogs hated him, it actually crashed through a plate glass window in order to attack Wilbur.
    • In At the Mountains of Madness, the expedition's dogs go nutzo over the strange beings they found frozen in a cave under the glacier. They're aliens (kinda) capable of extremely long periods of hibernation. However, they turn out to be not that evil, at least compared to what else the expedition finds under the glacier.
    • In "The Whisperer in Darkness", Henry Akeley's guard dogs can detect the presence of the Mi-Go when Akeley himself can't, and have an instinctive aggression towards them. As a result, he surrounds himself with them both at home and when traveling.
    • Lampshaded in "The Rats in the Walls", though it was a cat rather than a dog.
    "I realize how trite this sounds—like the inevitable dog in the horror story which always growls before his master sees the sheeted figure—yet I cannot suppress it."
    • In The Shadow Over Innsmouth, it's established that animals hate the Innsmouth people ("...they used to have lots of horse trouble before autos came in") and the narrator notices an absolute absence of dogs and cats around the town. When the townsfolk start chasing him out of town, he becomes very grateful that they don't have dogs. On the other hand, the novella's Twist Ending implies that "evil" might not be the best word to describe the Innsmouth people, and he may not have been in much danger in the first place.
  • In The Lovely Bones, the Salmons' dog Holiday howls in front of the home of Mr. Harvey, who murdered their daughter. Even more plus points to him that Mr. Harvey killed local animals too, so Holiday was right on the money to be warning little girls and pets alike.
  • Animals in general and dogs in particular tend to be afraid of the Dark Others in Night Watch (Series). They will never attack them but may bark. Tigercub does, however, train her dogs to attack all Others on sight but only to restrain them.
  • In Pact, the protagonist is generally hated and harassed by cats and dogs, who can tell that he is a diabolist, a summoner of The Legions of Hell. This proves to be problematic when he's trying to make the world a better place.
  • In Perdido Street Station, Lublamai's pet badger Sincerity is the first one to detect the threat of the runt slake-moth, growling downstairs as it emerges from its cocoon in Isaac's loft.
  • In L. Jagi Lamplighter's Prospero Lost, when Theo's dog accepts Mab's entry without complain, Theo visibly relaxes.
  • Rivers of London:
    • Toby, the dog that Peter acquires who moves into the Folly, is very sensitive to vestigia, and saves Peter from Molly's Horror Hunger after the hemomancy rite.
    • In the first book, it's mentioned that a blind man canvassing for charity donations who was slated to be the next victim of Mr. Punch was saved from the attack by his guide dog dragging him away.
  • E. F. Benson's "The Room in the Tower" features a dog who is very suspicious of Julia Stone's grave. Appropriately so, since she's a vampire. The pet cat, on the hand, can't get enough of the evil vibes.
  • The Saga of the Noble Dead features Chap and Shade. As majay-hi, descendants of Fay-possessed wolves, they have the innate ability to sense the presence of undead.
  • In Arthur Conan Doyle's "The Adventure of the Creeping Man" Sherlock Holmes asks "Why does Professor Presbury's wolfhound, Roy, endeavour to bite him?" Answer: because Presbury was injecting himself with ape glands to boost his virility, which made him act, and smell like, an ape.
    • "Silver Blaze", by contrast, famously includes "the curious incident of the dog in the night-time" — the curious incident being that the dog did not bark at an intruder, thus alerting Holmes to the fact that the dog knew the intruder, therefore the crime in question must have been an inside job.
  • The Starks' direwolves in A Song of Ice and Fire will growl at anyone their masters don't trust, and in at least two instances, someone they trusted but really shouldn't have.
    • Jon Snow's direwolf Ghost was also able to figure out that something was wrong with corpses they had found beyond the Wall after all other animals would not approach them.
    • Bran only trusted Sam Tarly after Summer, his direwolf, licked him. Sam remarking that he was friendly with Jon Snow's Ghost helped, too.
    • Mistakenly believing that Bran and Rickon's wolves failed to protect them, Robb stops putting any stock in Grey Wind as anything but a Right-Hand Attack Dog. As a result, against Catelyn's protests, he has his wolf sent away or chained up when he growls at Rolph Spicer and the Freys, whose grand betrayal leads to the deaths of Robb, Catelyn, and Grey Wind alike.
  • Sweeney Todd in A String of Pearls: A Romance, a pseudonymously written penny dreadful serial, is hated by a dog belonging to one of his victims. This actually forms a key part of the plot.
  • T2 Trilogy:
    • The Connors meet Dieter von Rossbach, the man whose appearance the T-800 Terminators is based on. Sarah assumes he's one of the Terminators, but realizes he is not when a dog acts friendly to him.
    • Skynet comes up with the I-950 Terminator, a brainwashed human enhanced by cybernetics. Since they are more human than machine, while it's noted that dogs still won't like them, they won't immediately blow their cover.
  • In Alexander Pushkin's The Tale of the Dead Princess and the Seven Knights, similarly to the animals in the Disney version of the same story, the knights' dog immediately welcomes the good princess and attempts to fight off the wicked queen. And when the latter fails, it whines and sniffles, trying to persuade the princess not to eat the poisoned apple.
  • Tuck Everlasting has cows. Yes, cows that follow a dirt path and quickly go around the forest that the main character flees into. That's one of the reasons why the humans also stay away.
  • In Red Death, a spinoff of The Vampire Files, the newly-risen and morally-insecure vampire Jonathan Barrett is reassured by how his family's dogs greet him with happy enthusiasm, averting this trope and suggesting he's not become evil.
  • In Andre Norton's Victory on Janus, the garth guard dogs, like the Iftin, can distinguish the Deceptively Human Robots from true humans and true Iftin by smell.
  • Not evil per se, but cats, dogs, and wolves in The Wheel of Time instinctively know whether a person can channel the One Power. Given male channelers' tendency to go violently insane from the Dark One's touch, this would come in handy for isolated villages, although the link doesn't seem to be widely known.
  • A Wind in the Door gives us a rare case of Louise the Larger, an evil-detecting snake who recognizes - and frightens off - a disguised Ecthros. The brothers have learned from experience to be wary of people the snake doesn't like. Possibly subverted with the revelation that Louise is a Teacher, though it isn't entirely clear if this actually grants her extra-sensory abilities and intelligence or if it is simply a cosmic "role" for an otherwise ordinary snake.
  • In The Woman in White, when Sir Percival greets Miss Fairlie's "little Italian greyhound", it whines, shivers and hides under the sofa from him, then barks and snaps at him when he leaves.
  • In the book The Zombie Survival Guide, dogs can sense zombies, reacting with maddened rage unless having been born in fully zombie-infested times. Taken further, in World War Z, dogs are specifically trained for zombie-fighting, helping escort special forces teams and scouts, and with smaller, tough breeds, going into areas humans cannot fight safely in.
    • Although all other animals take the second variety; one way of telling if a zombie is near you is if the wildlife is unnaturally quiet. This comes in quite handy in bogs, rain forests, etc., but applies everywhere.
    • Also in World War Z, one safe zone is shown using dogs in kennels arranged along a walkway as a screening process for refugees entering the city. If the dogs go nuts when you walk by... well, thought you could sneak into the safe zone with your infection, did you?

    Live-Action TV 
  • Parodied in 30 Rock. Tracy attempted to invoke this trope with his Rottweiler by training it to attack white-colored creatures, his logic being that since ghosts are typically depicted as pale white it would make the dog attack ghosts. The actual result was a dog that attacks white people on sight, including poor Kenneth who gets chased across New York by the thing.
  • On All My Children, Harold the dog is the only one to sense who psycho Janet Green really is. Both when she disguises herself as her sister Natalie and when she returns to town under a new identity after Magic Plastic Surgery, he is shown relentlessly barking and growling at her.
  • Subverted in Battlestar Galactica (2003), when Cylon D'Anna is quite pleased that Jake the dog doesn't react with hostility to her. Of course, little does she know that Jake serves La Résistance in another way.
    • Played straight in the original series with robot-Daggit Muffet, who could "sniff" out Cylons and cannibalistic aliens.
  • A light version of this appears in NCIS when Kate is reluctant to adopt a dog whose owner has died... until it growls at her Handsome Lech colleague who's always making unwelcome moves on her.
    • In the episode "Seek", Dex the military dog starts growling the moment he realizes he's in the presence of the man who murdered his handler in the opening sequence.
  • Episode 6 of Buffy the Vampire Slayer, Xander's change to evil is detected by a pig. Justified in that he later ate the pig.
    Buffy: He scared the pig! *Giles looks at her* ...Well, he did...
  • In Prue's penultimate appearance on Charmed, she is changed into a dog so she can detect the cries of a Banshee (who, by the way, is a possessed Phoebe) and lead Piper to her.
    • They also used to have an Evil Detecting Cat which hisses at and has been known to run from evil beings and demons, especially those trying to fool their way into the Halliwell household by appearing mortal. The "cat" comes back in a later episode, revealing herself to have actually been a human in cat form the entire time.
  • Daredevil (2015): In season 3 episode 11, the NYPD and FBI bring search dogs into the church to look for Matt and Karen, who are hiding in the basement. One of the dogs comes up to Dex, whose scent is all over the place from the attack he just committed on the church, prompting him to say, "Not me, fellas. The bad guys."
  • On Dexter (and the novels it's (loosely) based on), animals in general and dogs in particular can't tolerate the presence of the main character (a sociopathic serial killer). It's so bad that when he tried to keep a pet turtle it starved to death rather than come out of its shell when he fed it.
    • There's a dog that seems rather fond of Trinity in the fourth season, though.
  • In Dickensian, Miss Havisham's dog growls whenever Compeyson approaches. Eventually, he gets rid of the dog by throwing it in the river in a sack.
  • On The Dukes of Hazzard, Roscoe's dog, Flash, is very quiet and only barks at Boss Hogg. This became a plot point when Boss Hogg's ''good'' twin came to town, and Flash was used to prevent Boss from stealing his inheritance.
  • In The Event, dogs bark at the aliens, who are otherwise indistinguishable from humans.
  • In the Lifetime Movie of the Week Fatal Lessons: The Good Teacher, the not-good teacher is greeted with hostility by the family dog when she arrives to act as a nanny for the children (and later a cook). Her overall goal is to kill the wife and sexually torture the husband. The teacher, being something of a Mad Scientist, kills the dog by injecting it with a poison she concocted herself; she then buries the corpse and allows the family to think the dog ran away.
  • Happened several times in Forever Knight. A dog and a horse both reacted negatively to vampiric presences.
  • Game of Thrones: The direwolves, with maybe Lady as the sole exception. Ghost alerts Jon to the wight in Castle Black, Summer giving Jojen a Licked by the Dog moment leads Bran to trust him, and Grey Wind is very restless in his kennel just before the Red Wedding begins.
  • The Goes Wrong Show: The episode "90 Degrees" has Ruffles, the family dog, who would growl whenever he was near Renee (Vanessa) or Barbara (Sandra). Shame that said dog was voiced by Robert.
  • On The Golden Girls, Blanche discovers her current boyfriend cavorting with Rose's sister when the dog that they've been watching for a neighbor comes out into the living room carrying the man's pants. After being told off by an infuriated Blanche, the abashed man goes to get his pants and leave, only to be barked at and chased out of the house by the equally angry dog.
  • Played with on Heroes. Mr. Muggles always seems to know which characters shouldn't be trusted, but being that he's a tiny Pomeranian, there's not much he can do and he seemed to like a disguised Sylar and Revenge!Ted.
    • Played more straight in a deleted scene when Sylar has Claire trapped in a closet and Mr. Muggles goes mad barking at him but gets flicked out the doggie door for his trouble.
  • In Hotel Beau Séjour, horses can apparently sense Kato even though most humans can't see her. When she gets Buried Alive, the nearby horses start pawing at the spot where she was buried, alerting the farmers.
  • Subverted all the time on It Takes a Thief (2005)—the big, mean-looking dog the family owns as a thief deterrent is much more likely to approach the thief in a friendly manner or run away whimpering.
  • Kolchak: The Night Stalker. An evil pyromaniac ghost kills a man in his apartment through Spontaneous Human Combustion. When the ghost leaves the apartment, a dog in the corridor outside detects his presence and starts barking like crazy.
  • At the end of the Legends of Tomorrow episode "The Eggplant, the Witch and the Wardrobe," a dog starts snarling at Ray, who's surprised because animals usually like him. He then walks off whistling Neron's leitmotif, revealing that he's fallen victim to Demonic Possession.
  • MA Dtv had the one-off "Smith Comma John - Human Being for President" ads, one of which had him introduce Nilly, a golden lab who barked every time he tried to pet her.
  • The Magicians (2016): Variant. When Alice finds out she's being tracked by a lamprey, she buys a cat, paying special attention to its age, and starts carrying it around in a cage everywhere she goes. When the lamprey gets near, it starts hissing until it explodes in a bloody mess. She drops the cage and runs, leaving Quentin and the others to talk to a very confused cop.
    Quentin: Sorry, officer, a friend's cat was sick... and exploded. You know, like they do.
  • Not really evil detecting, but in My Own Worst Enemy the family dog is the only one who can tell when its owner's hard-edged split personality takes over.
  • In The Nanny, while C.C. wasn't evil (supposedly), she was a full-blooded Rich Bitch, and her Pomeranian Chester had no trouble letting her know it. He would snarl and growl every time she was anywhere near him, while being perfectly friendly to everybody else in the house. In real life, despite Lauren Lane (C.C.) being a very sweet and pleasant person, Chester was Fran Drescher's real life dog, and was so fiercely loyal to her that any time Lane picked up the dog, he would just naturally growl, so they wrote it into the story that way.
  • On Once Upon a Time, Dr. Hopper's dog, Pongo, is a well-behaved and sweet Dalmatian. But once Regina, the former Evil Queen, waltzes into their office, the dog starts growling at her and gets frozen for his trouble. That's because it's really Regina's mother Cora in disguise as her daughter. Pongo was previously shown being well-behaved around the real Regina.
  • The Outer Limits (1995): In "Stranded", Kevin Buchanan's German Shepherd Cody takes an instant dislike to Tyr'Nar while Kevin is completely taken in by his manipulations. Tyr'Nar solves the problem and satisfies his appetite by eating Cody.
  • Subverted in Prison Break. The dog begins barking at Haywire and then follows him down the road after he steals supplies from the camping store. It turns out the dog wanted the jerky in his backpack.
  • Invoked in Psych. Shawn is trying to fake a haunting in a house, and uses an electronic silent dog whistle to make a homeowner's dog start barking angrily. He then claims the dog is sensing an evil presence.
  • In Reaper, the first sign that The Devil has taken possession of Sam's soul is that dogs suddenly hate him.
  • In the TV adaptation of Scream, the opening victim Nina threatens the killer (whom she thinks is her boyfriend Tyler playing a prank on her) by telling him that she has a "trained attack Pomeranian, and she will gut you on command!" Her little dog does bark at the killer from behind the glass, but it does Nina little good when she's being stabbed to death.
  • Smallville:
    • In "Labyrinth", Shelby starts to bark in the presence of a phantom.
    • He does the same thing in "Veritas", when Brainiac drops by.
  • In Star Trek, it turns out that tribbles can detect disguised Klingons.
  • Parodied in Spaced, where a subplot concerns an anarchist who trained a dog to sense and attack rich people... Then he won the lottery and was immediately mauled by his own dog.
  • In Star Trek: Enterprise, Captain Archer's dog barks when a web-like alien passes in the conduits overhead. He also gets clearly spooked just before a Negative Space Wedgie manifests inside Enterprise herself.
  • Inverted in Star Trek: Voyager's Noir Episode. Tom Paris is accused of murder, and in the flashback scene the dog barks at him on sight. However the dog barks at all strangers, and Tuvok uses this to reveal the real killer, who's familiar with the house despite claiming otherwise.
  • Supernatural
    • Invoked Trope when Sam used this to explain why a dog kept barking at a house where a supernatural event had happened. It was never proved on screen, though.
    • Subverted in "All Dogs Go To Heaven". Sam and Dean are interrogating a man suspected of being a shapeshifter. The moment he enters the room, his own dog barks at him and the brothers exchange a Meaningful Look. Turns out the dog is the shapeshifter, and the man his next victim.
    • A subtle version in "Live Free or Twi Hard". When Dean is infected with vampire blood and is trying not to bite his Love Interest, a dog can be heard barking somewhere in the distance as he starts to go all fang-y.
  • In Tales of the Gold Monkey, Jake's one-eyed dog Jack growls or barks at any impostor, including the (unknown-to-the-characters) resident Nazi spy.
  • Terminator: The Sarah Connor Chronicles:
    • Dogs detecting Cameron as a Terminator react with dread.
      Carlos: Something about your friend I should know?
      Sarah: Cat person.
    • Played for Laughs when Cameron goes to a computer convention and a robot dog barks at her.
  • In the first episode of True Blood, a dog barks at resident Friendly Neighborhood Vampire Bill Compton.
  • The Twilight Zone (1959):
    • In "The Hunt", an agent of the Devil is trying to lure a recently-deceased Hyder Simpson into entering Hell. Hyder's dog Rip growls, warning him not to enter, and he avoids the trap. Later, an angel remarks "...a man, well, he'll walk right into Hell with both eyes open. But not even the Devil can fool a dog!"
    • In "Little Girl Lost", the Millers' dog Mack starts barking after Tina vanishes. When he's let inside, Mack runs under the bed and finds her in the other dimension.
  • The Twilight Zone (1985):
    • In "Teacher's Aide", Miss Peters' dog Muffin barks at her after she is possessed by the spirit of a gargoyle because he can sense that there is something very wrong with her.
    • In "Stranger in Possum Meadows", the Wilkins' dog Biff barks at Scout, who is an alien who intends to take Danny back to his planet for study. Scout uses his power over animals to quieten Biff and later takes the dog as a specimen. Although he eventually releases Danny, Biff is not so lucky.
  • War of the Worlds (1988): In "Amongst The Philistines", Kensington and Mrs. Pennyworth buy a dog just in time to have it react badly to Adrian, a few scenes before he turns out to be an alien. The trope is pretty blatant here, as the dog was introduced in this scene, and is never seen (alive) again.
  • Xena: Warrior Princess had Argo, her trusty horse that could tell something was wrong when Xena's body was hi-jacked by Callisto's spirit.
  • In The X-Files, "Terma", Soviet assassin Peskow manages to upset all the horses in a stable by calmly observing one of them. Though for all we know it was part of his plan.

  • Alice Cooper sings about how his dog and cat turn on and attack him in the final verse of "No More Mister Nice Guy".
  • Suggested by Loreena McKennitt's version of William Butler Yeats' "The Stolen Child", about mysterious faeries that seduce and steal away the titular child, which begins and ends with a chorus of barking hunting dogs who have detected the sinister faeries.

    Myths & Religion 

    Puppet Shows 
  • In Muppets Most Wanted, Animal realizes right away that Kermit has been replaced by an evil criminal mastermind.
    Animal: Bad froggy!


    Tabletop Games 
  • The Blood of Heroes RPG. Clint, one of the sample characters, has a dog that can detect evil.
  • Call of Cthulhu supplement Cthulhu Companion, adventure "The Rescue".
    • The first time the PCs meet Jael and Deborah Pelton is when they see them being threatened by a pack of dogs. The dogs are barking at them because they can detect that the Pelton girls are actually werewolves in human form.
    • Later, the adventure states that all animals react nervously or angrily whenever the Peltons come near.
  • In the Chill game animals (including dogs) can detect the use of Evil Way Disciplines or creatures from the Unknown up to 200 feet away.
  • GDW's Dark Conspiracy supplement Dark Races Volume I Compendium. When the evil monsters known as reavers are nearby, even if they're invisible, any animal (especially dogs) can sense their presence and will become uneasy. They start whining and shivering and refuse to enter an area with reavers in it.
  • In Deadlands: Hell on Earth, it is mentioned that during the war, dog were used to sniff out infiltrator cyborgs. Some survivor communities still use them for this purpose.
  • Dungeons & Dragons:
    • A Dragon magazine article on alternate familiars gave a spellcaster with a dog familiar a bonus to sense motives, using this trope as the reasoning.
    • Natural animals will usually refuse to approach a variety of undead creatures, so this can be a good way of searching for them.
    • Deities & Demigods Cyclopedia, Cthulhu Mythos section. Animals can detect the presence of the Evil creatures of the Cthulhu Mythos.
      All creatures of nature are very sensitive to the presence of all creatures of the Cthulhu Mythos. They instinctively call out their warning sounds and flee if any of the Old Ones or their minions come within range of their senses.
    • Dungeon magazine #38 adventure "Horror's Harvest". A number of people in the village of Delmunster have been possessed and changed into Chaotic Evil podlings by a doppleganger plant. All of the animals in the village (including horses, cats and dogs) will recognize their condition and react negatively to them. One of the dogs will actually viciously attack any podlings that come near it.
    • In The Gates of Hell fan supplement, it is mentioned that fiends of the Conversion Branch (the one in charge of manipulating mortal societies into serving hell), often take points in the Handle Animal skill precisely because of this trope.
  • Reversed in GURPS. The effect comes from entities with the Frightens Animals disadvantage rather than special powers that dogs have.
  • Magic: The Gathering has Thraben Purebloods, although they have this ability in flavor only.
  • This was one of the flaws of being one of the Pumonca Changing Breed in the Old World of Darkness Werewolf: The Apocalypse. As noted in their sourcebook, "All beasts fear the Pumonca. No horse will bear him, no dog will follow him." Apparently every other creature in existence except for humans can catch on to the fact you're actually an eight hundred pound werecougar in human guise and they all respond accordingly. This makes sense since cougars are one of the largest native predators to American soil, doubly so when they are some sort of werecreature, neatly explaining other animals' fear of them—to dogs, horses, and other animals, a large predator is a Very Bad Thing. This means it's less 'evil detecting dog' in most cases and more 'predator detecting dog.'
  • Pathfinder:
    • The Serial Killer Vigilante archetype has an ability, "Charming", which functions as a mundane effect equivalent to a charm hex to avoid suspicion in people — but not animals. A knight or inquisitor may be fooled by the vigilante's cool nature, but her horse won't be.
    • Animals can sense a spectre's unnatural and evil aura, and will not come within thirty feet of one of their own will. If forced within a spectre's presence, they will panic and attempt to flee as long as they remain too close to them.
    • The Warded Against Nature drawback makes animals avoid a character that has it like the plague.
    • Moon dogs (a kind of Neutral Good outsiders resembling slightly anthropomorphized afghan hounds) have Detect Evil as an innate magical ability, making them literal examples.
  • Chronicles of Darkness:
    • Promethean: The Created: The world at large hates Prometheans, and animals aren't any different. While Prometheans aren't evil, they are soulless and unnatural, and animals can instantly sense this and often move to attack. Of course, there's a whole school of Transmutations that allows them to redirect this rage in creative fashions...
    • Vampire: The Requiem: Vampires also have trouble dealing with animals unless they know the Discipline of Animalism, being living corpses. Conversely, if they do know Animalism, they can seem like a Friend to All Living Things.
  • The setting of Palladium's Rifts RPG takes the ball and runs with it; not only are animals explicitly said to be sensitive to supernatural evil, but one faction has genetically engineered anthropomorphic canines ("Dog Boys") specifically to exploit this ability as anti-supernatural police.
  • Shadowrun supplement Paranormal Animals of Europe. The kludde is evil vicious, and has Shapeshifting. Dogs and cats can always identify them no matter what shape they've taken: the dogs bark furiously at them and the cats hiss angrily.

    Video Games 
  • Another not-quite-evil-detecting example: in Assassin's Creed III, the British's dogs may start barking at you and grab the owner's attention, even if you haven't done anything "wrong" in front of it.
  • From the Command & Conquer: Red Alert Series:
    • In the first two games, attack dogs are a soviet unit that can detect spies that can fool any other unit and your base defenses. The allies also began to use them in the second game.
    • In the third game the dogs still use by allies force while the soviets one ups this by replacing them with armored war bears.
    • In Red Alert 3: Paradox, you need to use each faction's animal scout unit to detect stealth units, which is not only limited to Evil Detecting Dogs but Evil Detecting Bears, Hawks, Tigers, Sharks, and Giant Robot Crabs too.
  • Dragon Age has Mabari warhounds - extremely intelligent animals capable of understanding human speech. As a general rule, they have this going on, since you can only get a Mabari to agree to be your pet if it decides you are a sufficiently good person. The Mabari were bred by a wizard to bolster the forces of Tevinter, but according to legend, the dogs changed sides when they met the much kinder Fereldan natives; they have been the symbol of the country ever since. It's also stated that the reason Mabari originally became so popular in Ferelden was because they can detect werewolves.
    • Dragon Age: Origins has several examples, but they're only seen if your faithful Mabari warhound is in the active party:
      • In the Human Noble origin (the only one where you have Dog from the very beginning), Dog is introduced as having figured out that there are large and rather dangerous rats in the castle larder. Later, his barking is what alerts the PC to the fact that the family castle is being invaded.
      • In the Stone Prisoner DLC, Dog will immediately sense that "Kitty" is something powerful and evil and that's before the ominous glowing eyes and ominous demonic voice come into play.
      • In the "Nature of the Beast" quest, Dog's hostility towards Zathrian serves as an indication that he's not the most trustworthy fellow.
      • In the Warden's Keep DLC, Dog will immediately sense the demon possessing Sophia Dryden.
      • During the "Sacred Ashes" quest, Dog licks an ominous desk covered in blood, and starts to growl at it, noting that something is not good within Haven. He's right, of course; the place is home to an evil dragon-worshiping cult.
      • Inverted with Dog being reserved and occasionally hostile to Alistair, yet affectionate toward Morrigan. (Alistair isn't a bad guy at all - quite the opposite; Dog just doesn't like him because he's made too many jokes about taking Dog's food.)
    • If the Black Emporium DLC is installed for Dragon Age II, Hawke can express a preference for their Mabari to stay with their mother Leandra at all times, because his strength and evil-detecting abilities offer her excellent protection. Later, the dog has a brief scene in which he successfully captures a would-be thief in Hawke's closet.
    • There's no Mabari for the Inquisitor in Dragon Age: Inquisition, with the in-game explanation being that, unlike the Warden and Hawke, the Inquisitor is not from Ferelden (and Mabari are pretty much exclusively Fereldan). However, it's been speculated that it was really for precisely this reason - a Mabari would likely have been able to determine that one specific character was not what he was claiming to be.
  • Fallen London: The Bishop of Southwark wants you to breed one of these, the fabled "Hound of Heaven", to root out devils in the Labyrinth of Tigers. Despite the Bishop's repeated admonition of "no serpents!", the Hound turns out to be just that — a glowing white snake with evil-detecting red eyes.
  • Works awesomely well in Fallout: New Vegas: in one of the final missions of the game, if you think to take your robo-dog Rex with you as a companion, he will detect a Legion assassin in disguise without you having to search for him. Subverted since you discover he was once a Legion-owned dog, being the companion of Caesar himself, making this arguably more of a They Have the Scent!. Played straight if you have the Animal Friend perk and use a lender-dog to do the same thing.
    • Faction-owned guard dogs are also able to see through the player's disguises.
  • In Final Fantasy VII, in the flashback to when Tifa found Cloud lying unconscious in the train station, a dog is barking at him, trying to revive him and even running to Tifa to get her to help him. It stays friendly with Cloud until Cloud's SOLDIER persona is fully in place, at which point the dog runs a distance and turns around to bark at Cloud aggressively, able to tell that he's suddenly changed into something else.
  • In Geist, dogs can sense you as a ghost, and know something is up when you're possessing somebody. The Big Bad knows this and exploits this, keeping dogs at various checkpoints to make sure you don't escape through a soldier. You can't escape in ghost form, due to energy shields that only let solid matter pass through.
  • At the beginning of Guenevere, Guen gets a fae pet (either a cat or a dog) who has a preternatural sense for those trying to do his mistress harm and is willing to act on such feelings immediately and violently.
  • In Fate/Grand Order, the Shinjuku chapter features the protagonist thrown into a Wretched Hive, and even their allies for this chapter have canonically Evil alignments. The All-Loving Hero protagonist soon befriends a dog who acts as a barometer on how "good" an ally is despite their alignment and temperament. One of their first allies is Altria Alter, who basically adopts the dog and names it Cavall II, and she sticks to the party through thick and thin as one of the main allies despite her protests otherwise. Meanwhile, their first ally Archer of Shinjuku gets mildly harassed by Cavall throughout the chapter, and Hassan of the Cursed Arm gets outright growled at. Per the trope, the latter is revealed in the cutscene right afterward as the cruelly antagonistic Assassin of Shinjuku in disguise, while Archer has been suspicious since the beginning even after revealing he's the "good" counterpart to the true villain. And at the end of Shinjuku... Well, he's the bad guy after all, but his spot of goodness ends up foiling his plan.
  • Hewie from Haunting Ground barks at hidden traps and other unseen dangers, allowing the mostly helpless Fiona to work around the many perils of Belli Castle.
  • Haunting Starring Polterguy: The family's dog (a very ugly chihuahua) can detect poltergeist Polterguy and will bark at him to make his gauge of ectoplasma drop. He also can calm down the family members so you have to scare them again. The only thing Polterguy can do against the dog is using a magic spell (found in the underworld) to give him food. He will turn into the final boss by the end.
  • Despite disguises, dogs in the Hitman series will often, if not always, sniff Agent 47 out.
  • In The Legend of Zelda: Breath of the Wild, Link can purchase the "Dark set" of armor that will make him look like Dark Link. Regular NPCs will freak out upon seeing him in this shadowy outfit, even those who are close friends of his. Hylian Retrievers, on the other hand, will not freak out and will react happily to him giving them food, spinning in circles, etc., just as they would when he wears other outfits. This game also adds Wolf Link, who can detect camouflaged Lizalfos and enemies hidden in the player's field of vision.
  • Life Is Strange: In a weird case, the local drug dealer's dog acts like this. Should Max tell Frank Bowers that Nathan's Accidental Murder of Frank's girlfriend Rachel he recalls that Pompidou hated Nathan and berates himself for not trusting his dog's instinct.
  • In Long Live the Queen, you can get an important clue if your Dogs skill (under Animal Handling) is high enough. The dog barks at the scent of poisoned chocolate, saving Elodie from assassination.
  • In Mega Man Legends, a local dog knows that Tron Bonne (a Pirate Girl) is up to no good.
  • Metal Gear:
    • In Metal Gear Solid, Sniper Wolf's wolf-dogs are not fooled even by your Optic Camouflage. The only way to get past them without hassle is to have one of the puppies piss on your cardboard box, or to have Wolf's handkerchief equipped.
    • Not exactly evil-detecting, but at one point in Metal Gear Solid 3 you need to put on an enemy uniform and mask to infiltrate a base. Scientists, guards, and security cameras take you for the real deal and don't raise alarms. But you don't smell like the officer you're impersonating, and guard dogs will still raise alerts.
    • Used symbolically in the opening cutscenes of Metal Gear Solid V: Ground Zeroes when the Camp Omega guard dogs are barking furiously and lunging at Skullface and need to be held back by their handlers. While it's clearly because they, as guard dogs, simply don't recognize him as one of the camp's personnel, it also makes it very clear this guy is bad news and means to cause some serious damage. Oh boy are they right.
    • Metal Gear Solid V: The Phantom Pain has a very straightforward example in the form of Big Boss' loyal pet D-Dog, who has the ability to sense and bark at the presence of any nearby enemy soldiers (and also prisoners-of-war, wild animals, various objects such as weapons and vehicles, etc.); conveniently producing onscreen markers for the player to find them.
  • The trope is discussed in Mortal Kombat 11, during a pre-fight dialogue exchange between Terminator and Kotal Kahn.
    Kotal Kahn: Barking dogs heralded your arrival.
    Kotal Kahn: Helpful, indeed...
  • In Mother 3, Lucas, Kumatora and Duster eat some unusual mushrooms while desperate for food. The mushrooms cause them to hallucinate that the monsters in the area are characters from their pasts. The party dog, Boney, is the only one not fooled, and whines and barks when the hallucinations begin to talk to the characters, attempting to warn the rest of the party as to their true nature. He also refuses to get into a beautiful sauna the party can rest in - if you visit it again after the effects of the mushrooms have worn off, you'll find the humans were deliriously bathing in toxic sludge.
  • A literal case in NetHack, where your pet (typically a dog) will hesitate to step on cursed items.
  • Inverted in the Oddworld series. Slogs, the villains' guard dogs, can sometimes detect when the player has possessed a slig and will attack him as viciously as they would you.
  • In Ōkami, Amaterasu is a goddess taking the form of a white wolf. She's often seen preemptively reacting to threats before they appear onscreen. While Issun can usually also feel when a particular place has a bad vibe, there is one particular scene where this trope is played straightest: when Amaterasu comes across a dead Queen Himiko and finds Rao also present and claiming to have witnessed the queen being attacked by a demon, Ammy immediately realizes that Rao is not who she says she is and attacks her. Issun thinks Ammy has gone crazy until "Rao" lets out an Evil Laugh.
  • Koromaru in Persona 3. He's the first indication that non-humans can have a Persona (his, appropriately, is Cerberus). Taken to its natural conclusion in Persona Q2: New Cinema Labyrinth, where he catches on to Goro Akechi quickly. (Probably due to realizing how similar he is to Ken). Unlike most examples, however, he latches onto them because he wants to help them overcome their hatred rather than point them out.
  • In Pokémon HeartGold and SoulSilver, your Pokémon will react negatively to the Persian Statues (which are actually security cameras) while inside the Rocket Hideout.
  • In Robopon, this is inverted. The dog is evil or at least under the care of villains, and growls at Cody when he approaches.
  • Brown from Rule of Rose works very much like Hewie and can detect and bark at enemies long before Jennifer (or the player) can see them. He can also sniff out items though these aren't exactly "evil".
  • When you first enter the main city in Shining the Holy Ark you see one of the villains walking around. A cute little puppy starts barking like crazy at her, then a flash of light blinds you; when you can see again, she's gone and so is the puppy, leaving a crying child.
  • The Escapists 2 features these. Dogs can detect and sniff out contrabandnote  but will not attack unless there is a lockdown.
  • In The Sims 3, cats and dogs will "investigate the strange sim" if there is a vampire nearby and there will be a talk bubble on their head with a picture of bats.
  • In Snatcher, it's commonly believed that animals can detect Snatchers, to the point where genetically engineered "Pocket Pets", which can be used as purses, are becoming extremely popular.
  • In Super Paper Mario, there is a large guard dog-esque monster in Merlee's mansion who is chained up. When released, he runs past Mario and chases off the mansion's maid, who is actually one of the Big Bad's minions, the shapeshifting Mimi.
  • Used in Super Robot Wars Advance. The pet dog from Zambot 3 is able to detect that something is kinda off to the protagonists, who's actually a Shadow Mirror spy. Axel gets a typical bark, but the dog barks louder to Lamia, who is actually a Robot Girl.
  • Parodied in Kagetsu Tohya. Shiki learns that a black cat (Len) frequents the Tohno mansion courtyard, but only lets Hisui approach it, and he wryly comments that animals really can sense dangerous people. Akiha and Kohaku are decidedly not amused...
  • Some enemies in World of Warcraft have watchdogs that can see through stealth.
    • Hunter pets will also occasionally stop dead in their tracks if they detect a stealthed hostile mob or player. One of the many reasons for a Hunter to learn to keep an eye on their pet.
    • The warlock pet Felhunter (bascially a demon dog) used to provide his allies with increased stealth detection. These days, the Voidwalker instead does something similiar while he uses his selfhealing ability Consume Shadows.

    Web Animation 
  • DSBT InsaniT: In 'Store Story', Autumn brings this up after Chilly, Frog, Perry, and Snake suddenly up and leave the pet store due to Stephanie's Siren-like brainwashing.
    Autmn: Wait! Where are you guys going?! Is this an animal thing?! Do you sense an earthquake or something?!

    Web Comics 

    Web Original 
  • After this news report hit the internet, 4chan started claiming dogs could "sense" members of the site.
  • In Tales of MU, dogs can detect the main character's ancestry and are utterly hostile to her. This naturally results in her being afraid of them.
  • In the Ted the Caver webfiction, a Jack Russel terrier named Trip refuses to go into a sinister cave the protagonists are investigating.
  • In the Creepypasta called My Dog Won't Stop Staring, a college student adopts a little mixed breed dog named Ruby to keep him company. Not long after he adopts her, though, Ruby starts staring at him, both unnerving and irritating him, so much so that he starts treating her roughly. It turns out that Ruby has seen a demon sinking its claws into her master's shoulder, and she's fiercely staring at it to leave her master alone.
  • The Onion Radio News: "Family Dog Barking At Evil"
  • Reddit has rapist_sniffing_dog and racism_sniffing_dog.
  • In SCP Foundation, SCP-1495 ("Karmic Musth") is an anomalous herd of elephants. Once a year, some elephants turn into SCP-1495-M, which can control other animals. They can identify people who have acted in an evil manner and order the animals to attack and kill them.

    Web Videos 
  • In Everyman HYBRID, Alex's dog Sparky detects The Rake long before its first attack on Alex, and may well have been keeping The Rake from attacking while Sparky was in the room. Interesting given The Rake itself is a freakish dog-man.
  • In Marble Hornets and Seeking Truth, dogs do not react well to the presence of the resident Humanoid Abomination.
  • Mocked by Diamanda Hagan in her Apocalypse 2: Revelation review:
    Diamanda: Because, as we all know, no-one evil has ever gotten on the good side of a dog. [cuts to picture of Adolf Hitler with his dog] Oh, right.
  • When Table Flip plays Betrayal at House on the Hill, they discover a Dog companion named Fidonkers shortly before the Haunt begins and the Traitor is revealed. Fidonkers then barks and growls at the traitor accordingly.

    Western Animation 
  • Avatar:
    • Avatar: The Last Airbender:
      • Appa and Momo are very good at detecting malicious intent in humans. Appa growls and reacts defensively towards the sandbenders (who later capture him) and Momo hisses at the pirate captain and his weird bird thingy. In fact, it's Appa licking Zuko that makes Aang wonder if he's really changed.
      • On the other hand, the Earth King states of his pet bear: "if there was any danger at all, Bosco's animal instincts would sense it." Granted, Bosco had been apprehensive around Azula, but the King had misread that as exhaustion; when he uses this line, it is in extreme error.
    • The Legend of Korra:
      • In the episode "And the Winner Is...", the fire-ferret Pabu sits peacefully by the radio while music plays, but hisses at it and jumps away when Amon pulls a Do Not Adjust Your Set in the middle of the music program.
      • Naga the bear-dog also senses a dark spirit in "Rebel Spirit".
      • Another Pabu example from "The Terror Within". He notices the Red Lotus sneaking in to kidnap Korra twice; once when they're on their way to her room, and the other when they actually managed to kidnap her. While he shrieks both times, he only manages to wake Bolin up the second time, though.
      • An adorable puppy greets Korra in "Korra Alone" and is able to see her hallucination self easily. That's because a spirit can detect other spirits too, and the puppy is actually the little leaf spirit she meets in the Tree of Life.
  • Ben 10:
    • In Ben 10: Ultimate Alien, Ship is amazingly skilled at detecting enemies:
      • In the episode "Eye of the Beholder", Ship detects that his father Baz-El is in trouble and flies away in his Anterian Obliterator form to rescue him.
      • In the episode "Perfect Girlfriend", Ship barks and growls at "Julie" who is later revealed to be a Not Quite Dead Elena disguised as Julie to manipulate Ben and steal him for herself.
      • In the Grand Finale, Ship senses the Esoterica wave and shields Julie from it by merging into a battle armor around her.
    • Zed from Ben 10: Omniverse plays this as well, as seen in "Mystery Incorpreal" where she sniffed and growled at Gwen's classmate, Dante, who turns out to be Darkstar wearing an ID Mask.
  • The titular protagonist of Courage the Cowardly Dog is a talking dog who often senses the presence of evil and/or strange creatures around him. Courage will always try to warn his owners Muriel and Eustace, but they never pay any attention to his panicked ramblings.
  • DC Animated Universe:
    • Batman: The Animated Series: Inverted example in one episode; while Harley Quinn, recently released from Arkham Asylum and out trying to start a new life, her hyenas immediately start barking at the sight of Bruce Wayne. Harley for her part is clueless that she happens to be standing right next to Batman himself.
    • Batman Beyond: Bruce Wayne's dog Ace can be quite aggressive towards the bad guys. In Batman Beyond: Return of the Joker, he even attacks The Joker himself.
      • Ace can also detect supernatural phenomena. In one episode, Terry is asked for help by a young girl with psychic powers. When talking with Bruce about this, Terry manages to see the girl (although no one else can, since she is using her powers). However, Ace becomes alert and defensive, being able to detect the girl's psychic presence (even though she's not really there and only Terry can see her). She is not evil at all, though.
  • Defenders of the Earth has the following examples:
    • In "Ming's Household Helpers", Zuffy freaks out when Rick brings one of the robots with which Ming plans to enslave humanity via hypno-beam into Monitor.
    • Zuffy also gets scared around the title character in "The Starboy", an alien child who has destroyed whole worlds. Played with; Starboy is not inherently evil and only lashed out because he was afraid of being left on his own.
    • In "The Frozen Heart", Kisa growls at LJ's girlfriend, Kate, who has been turned into one of Ming's Frost People.
    • In "Flash Times Four", the Defenders are tricked into rescuing one of Flash's clones (instead of the real Flash) from Ice Station Earth. No-one notices that anything is amiss - except Zuffy.
  • In the Ed, Edd n Eddy episode "Run for your Ed", the Kankers lose their family 'Ship Inna Bottle' due to Ed's sleepwalking. They decide to search the Cul-de-sac in their usual chaotic mischief, which results in mass destruction. Prior to that, Rolf's animals catch on to their impending visit and all flip out (from his goat standing stiff, his chickens and pig screaming and flailing around, and even a piece of fried chicken seem to give some reaction to Rolf when put against his ear). When he realizes what's going on, Rolf quickly carries all his farm animals into the basement and closes it, waiting there for the rest of the episode.
    Rolf: "The stench of immortal doom still thickens the air, yes? Or perhaps it is Wilfred's cabbage evacuations. Hard to tell."
  • Parodied in Family Guy: Trying to score a date with his crush, Death steps into her pet store to talk to her. The animals inside raise such a commotion that they can't hear each other.
    • Also, Brian the dog is the only one who realizes Stewie is evil. Of course, that is more that he is the Only Sane Man on the show.
    • In "And Then There Were Fewer", Brian growls when James Woods shows up.
  • In the Galaxy Rangers episode "Mindnet," the first clue to the characters that all is not right is when Icarus and Winter (a pair of cybernetically enhanced dolphins) protest that "Goose" is behaving strangely. (The first clue to the audience is that Killbane's voice actor is trying to imitate Doug Pris and isn't doing very well).
  • Bronx from Gargoyles is a dog-like gargoyle beast who sometimes starts barking and growling when there's something dangerous and/or supernatural nearby, in order to alert his friends to the problem.
    • In "City of Stone: Part 3", Bronx starts clawing at one of the tapestries just as Goliath and the clan are about to implement Xanatos's plan to end Demona's curse. When the gargoyles are gone, Demona comes out from a secret passage behind said tapestry with a mace, ready to smash Elisa to bits and dispose of the others.
    • In "The Hound of Ulster", Bronx takes a liking to an Irish teenage boy, but growls and barks at his female friend. Turns out that his friend is actually the Banshee in disguise, and that she was only acting as his friend to keep him from discovering that he is the reincarnation of her warrior nemesis.
    • In an actual canine example, Jeffrey Robbins's dog growls when he first spots the recurring antagonist Macbeth in "A Lighthouse in the Sea of Time".
  • Hey Arnold! The Jungle Movie: While on the boat, Abner the pig comes to sniff Eduardo (who is really Big Bad Lasombra in disguise). When the pig smells his scent, he squeals in terror and tries to warn Arnold before heading back to America to warn his grandparents.
  • Jonny Quest TOS episodes.
    • "Skull and Double Crossbones". When Jose asks Bandit if he wants to be friends, Bandit growls at him. Later we learn that Jose is The Mole, a spy for the Chief of a crew of pirates.
    • "Shadow of the Condor". When Bandit first meets Baron von Freulich he growls at him. Later von Freulich tries to murder Race Bannon.
  • Somewhat inverted in Kim Possible, where pretty much all the villains seem to hate Rufus, but they like him if turned good (both Shego and Draken can be called as witnesses)
  • Kipo and the Age of Wonderbeasts: Mandu's usually the first to sense danger. She also expresses her disapproval when members of the group are behaving badly.
  • In the somewhat forgotten kids' cartoon The Magician, an Identical Stranger (thanks to plastic surgery) kidnaps and switches places with the eponymous main character, taking care to plant a behavior modification chip on his pet dog to ensure it will bark distrustfully at the real guy, and stop doing so at him, which is useful to fool the sidekick.
  • In the My Little Pony: Friendship Is Magic episode Inspiration Manifestation, Owlowiscious picks up that there's something wrong with the book right off the bat, and of course tries to dissuade Spike from taking it.
    • Although you really don't have to be specially evil-detecting to think that a stone-grey book with spikes jutting out of the cover and hidden in a secret locked room of a castle ruin is probably something you should leave alone.
  • Inverted in Phantom 2040: DV-L is initially uneasy around Kit, so Sagan has to firmly tell him that Kit is a friend. Later on, when they meet Kit as the Phantom, Sagan expects DV-L to attack... but, of course, DV-L remembers that he's a friend and lets him go.
  • In the Van Beuren Studios Rainbow Parade short "Scottie Finds A Home", the eponymous terrier knows right away that the vagrant who arrives at the grandmothers house is up yo no good. After barking at him, the hobo hangs him by his sweater on a nearby tree as he goes off to pester the grandma cat for food.
  • A variation in Reboot: Enzo's dog Frisket is a pretty good judge of character, but he hates Bob, the main hero.
  • A Robot Chicken skit has this happen with a child instead of an animal; O.J Simpson tells his grandson about how he didn't kill his wife (it involves Roger Rabbit) and the grandson starts bawling his eyes out. When he asks whats wrong, their maid tells him he can sense evil.
  • In Samurai Jack, animals tend to be wary of Aku, who is a giant demonic entity. It's justified because Aku is the most dangerous villain in the universe, and is justly well-feared by everyone who knows of him.
  • The Simpsons:
    • In a Deleted Scene from "Treehouse of Horror V", the Simpson family's pets, Santa's Little Helper (the dog) and Snowball (the cat), along with Maggie, all start growling when Bart (who had recently been turned into a vampire) floats into the kitchen.
    • In "Bart Sells His Soul", after Bart sells his soul to Milhouse, Santa's Little Helper and Snowball both growl at him.
  • The Mask: Milo still gets scared of the Mask of Loki so he goes under the bed when his owner puts it on and the Painful Transformation starts. The same with Esmeralda as she sees that her owner has become a different woman literally after accidentally putting on the mask. Though Milo does eventually see that his owner's alter-ego The Mask is a good-hearted, nice and kind man so he gets less scared of his owner putting it on since he can finally see just how much The Mask cares about Milo and loves him very much along with he also wears it when he has to rescue his owner from danger as well.
  • In an episode of the Spider-Man and His Amazing Friends 80's series, Aunt May's puppy became a living lie detector, since thanks to her sense of smell she could point out who had his or her place stolen by shapeshifting villain The Chameleon.
  • The Zillo Beast in Star Wars: The Clone Wars is able to tell that Palpatine is evil and, upon escaping from its cell, rampages through Coruscant to hunt him down for that and for Palpatine being the one who sentenced the creature to death.
  • Radarr, Team Pet of the Storm Hawks, detects evil in two episodes that were broadcast consecutively.
    • In "Best Friends Forever", Big Bad Cyclonia disguises herself as an ally of the team. At first, only Radarr is able to sense that something's wrong.
    • In "The Black Gorge", Radarr is suspicious of a seemingly harmless animal who eventually transforms into a monstrous Gorge Sloth.
  • In Super 4, Alien growls at fairies who actually Sykronians in disguise. When he doesn't growl at Alex, Gene realizes that he must be the real Alex.
  • Victor and Valentino: Valentino takes his new girlfriend Matty to the local cat cafe. All the cats freak out and start hissing at her. She tries to play it off as cats being allergic to her, however she's actually a monster in disguise. She just wants to fatten u Valentino and eat him.
  • Grougal from Wakfu (a baby dragon) really does not like Qilby. But there's a whole lot of history around this.
  • In the second season of W.I.T.C.H., Big Bad Nerissa is capable of using illusions to disguise herself as any other person. However, Matt's pet dormouse Mr. Huggles always goes berserk in her presence, no matter what she looks like.

    Real Life 
  • The obvious origin of the trope is guard dogs being used by humans to alert them of the presence of predators and enemies, due to their senses of hearing and smell being much more developed than ours.
  • Dogs (and cats) have been known to react in the alleged presence of the supernatural.
    • There is a persistent myth that if a dog or horse freaks out, and there is nothing visible to you that should be causing them to do so, one should look at what the animal is looking at. More specifically, to do so by looking between their perked ears. The myth states that you will see the spirits or ghosts that only animals normally see if you do this.
  • Older Than Feudalism: In Zoroastrianism, one of the oldest surviving faiths in the world, the dog is considered one of the most sacred animals for its ability to detect, and even deflect, evil with a mere gaze.
  • Some dogs also seem to be able to sense the presence of tumors and even predict when epileptic owners are about to have seizures. In the case of tumors, this is because cancer cells smell distinctly different from a normal cell. In the case of seizures, the biochemical reactions that precede them cause a subtle shift in the person's scent, and other things like heart rate.
  • Purportedly, head Scientologist Dave Miscavage's dog.
  • The book The Gift Of Fear says that when a dog growls at a shifty person, it is actually responding to the owner's unease and trying to protect them.
    • Not unlikely at all, given dogs are capable of detecting their masters' emotions, even hidden ones, thanks to their senses. (They can hear a heartbeat speeding up, for one.)
      • Dogs are also incredibly attuned to body language, since the bulk of their communication is by that method. Since dogs and people share a number of signals, they can easily pick on things we'd miss since we tend to focus on tone of voice.
      • Seizure response dog and diabetic alert dogs are trained to predict upcoming attacks and warn their owners. Even untrained dogs are told to be sensitive for sudden changes and attempt to protect humans from harm - barking, forcing them to lay down or even bite their hands, forcing them to drop sharp objects like knives and scissors before the seizure begins.
      • There is one account of a horse that did the same thing, and would answer math questions and puzzles by reading the unconscious body language of humans present and responding by tapping his hoof or pointing to an object. It was only figured out when a psychologist asked the horse a question nobody knew the answer to, and the horse couldn't figure out how to answer.
      • Another version says that the horse "counted" by hitting the ground with its hoof and stopped when its owner made a small nod - often without even realizing it, relieved that the horse had got the "right" answer. When the horse was put to count in a room without his owner, he kept on counting.
      • Konrad Lorenz describes a case with such a dog; it was shown a paper with a simple math question, but with paper glued on the other side so it will show a different question for the dog's owner, who was looking at the back. The dog, naturally, answered the other question. Then they put a rag in front of it, and asked what it smelled. The dog's behavior made it quite obvious it knew the answer; a female in heat, but the owner wasn't that good in reading animals, so the dog tapped out "Cheese".
  • A specific example is the Pekingese, a dog that Chinese Emperors used to keep inside their sleeves. If the dog bit someone who had been granted an audience with the Emperor, it was a sign they were untrustworthy, which usually meant execution.
  • True crime author Ann Rule's dog always snarled and growled at her friend Ted Bundy and shied away whenever he tried to pet him, despite usually being friendly to everyone. Little did Ann know her friend was a serial killer spending his nights prowling college campuses for victims. Similarly, the cat belonging to the sorority house where he went on one of his final rampages apparently ran away the night of his attack. In an interview with one of the surviving victims, she speculated that the cat must have sensed the impending threat.
    • Mark Harmon claims his own dogs were wary of him while he was playing the role of Bundy in the miniseries The Deliberate Stranger.
  • Likewise, the neighbor of Josef Fritzl (the Austrian man who kept his daughter locked in the basement for years and fathered incestuous children with her) insists that his usually-friendly dog absolutely hated him.
  • A similar occurrence happened with the East Area Rapist/ Golden State Killer / Original Night Stalker (or EAR-ONS, in police terms). He would strike houses in California, commit petty theft, rape the occupant and then leave. However, it is widely believed he would extensively stake out an area beforehand, both on foot and using hang-up calls. Dogs in the area would bark at the dividing fences between houses or at something in the back yard, even if the owners couldn't see what was winding them up. A woman also received a knock on the door from a local man whose dog had been injured after chasing after something, which was also believed to be linked to EAR-ONS (the dog got medical help and was fine; the man later sent the woman a thank you for her assistance).
  • Not strictly "evil" per se, but almost all animals have some form of precognition when it comes to natural disasters. So, in this case, humanity really is Too Dumb to Live! No, seriously. Ask anyone who's been through a major earthquake. Dogs, cats, horses, birds, they all freak out. And get out, if they can.
    • Most animals can hear the surface noises generated by the initial p-waves of an earthquake, though this sound is too high in frequency for human hearing. Chinchillas, which have hearing abilities roughly similar to humans, are just about the only animal that will not freak out shortly before an earthquake hits.
    • After the Boxing Day Tsunami, there were reports that elephants kept at a vacation spot in Thailand became agitated, put tourists on their backs and moved to high ground just before the wave hit, saving them.
    • George Clooney credits his pet pig Max with saving his life in 1994, saying the pig woke him up before an earthquake dropped a beam over the bed they were sleeping in. Since Clooney got his Star-Making Role in ER months later, and he Sleeps in the Nude, we can also say that Max is responsible for Clooney not becoming famous for the wrong reason.
  • Dogs and rats have been trained to detect land mines or gas leaks by smell.
    • In the 19th century miners used to keep small birds for the purpose of detecting gas. From the troper's perspective, this would have been a Deconstruction of the trope since the birds were not there to be a living alarm bell, but rather to pass out or die before gas concentration could affect a human. This also gave us the phrase "Canary in a Coal Mine."
  • Despite the above examples, this trope shouldn't be relied on in Real Life, as plenty of animals make a habit of reacting badly to strangers in general, or to specific types of people (all men, tall people, folks wearing hats, etc.), regardless of demeanor or intent. i.e., a badly-socialized dog will freak out at anyone approaching it in a manner that scares it, or an abused pet can react badly to anyone who accidentally does something that triggers bad memories.
  • Not quite "evil" exactly, but any animal that can not detect (and prevent) a predator's "evil" attempt to eat them, will not be around to breed the next generation of evil detecting animal. This applies to most dangers as well.
    • Particularly true of snakes, which many animals' brains are hardwired to notice even if they're camouflaged.
    • The patas monkey, a land-dwelling social primate from the African savanna, has three vocalizations for danger meaning "snake", "leopard", and "eagle" (or more generally, "danger below", "from the side", and "above"). It is speculated that human language once began the same way.
  • The "evil" aspect depends on a subjective value, but there's Lucky and Flo, two black Labradors that the MPAA praised for their ability to sniff out counterfeit CDs (and legitimate ones).
  • A blind man who was on the 71st floor of the North Tower of the World Trade Center released his guide dog from his harness so that the animal could escape (he feared that he would never make it down the stairs in time and wanted to give the dog a chance). The dog came back and pawed at him until it was finally obvious that he was not leaving without his master. He then proceeded to lead his master down 71 flights of stairs to safety. Guide dogs receive extensive training, but this still had to be a very perceptive animal to realize that this was an incredibly dangerous situation and he had to get his master out of there.
  • Philosopher Diogenes of Sinope, who often compared himself to a dog and argued that people should aspire to learn from them, claimed that this was one of their virtues: He believed they always knew, instinctively, who their friends and enemies were.
  • Feral dog packs can discern when one of their number is acting oddly due to rabies infection, and quickly expel the sick animal from the group or abandon its company.
  • More than one unit mascot dog in World War I and World War II gained reputations for predicting artillery barrages.
  • The muntjac, a small deer-like animal from Southeast Asia, makes some characteristic "barkings" to alert other members of its species when they know that a tiger is near. Many animals of other species (and people are not an exception) have learned the meaning of this barking and become wary when they hear it. And bear in mind that muntjacs are quite small and have a talent for camouflage, so they could save your life without you ever seeing one.
    • Similarly, in Africa most animals have learned to keep one eye on the giraffes. If the giraffes start running it's because they've seen something from their height worth running from, like a lion. Ostriches take on a similar role in areas where they are present but giraffes are not.
    • Also common in other parts of the world, e.g. North American wild turkeys often stay close to white-tailed deer, trusting the deer will smell danger before the turkeys do; the deer likewise count on the turkeys' keen eyesight to spot threats.
  • Prosecutor Alice Vachss got a retired seeing eye dog as a pet. Normally it would sleep in her office and ignore everyone, but if it got up while Vachss was interviewing a child abuse victim, that child always would need serious therapy.
  • Invoked with drug- and explosive-sniffing dogs, which are specifically trained to detect nasty materials and alert their human handlers to what they've sensed.
  • On a number of occasions, a couple discovered that their babysitter was abusing their child because their normally gentle dog turned aggressive whenever the babysitter came over, or a cat was being actively hostile towards the babysitter.
  • While not technically "evil" he's detecting, but Oscar, a cat at Steere House Nursing and Rehabilitation Center in Providence, Rhode Island, is known for napping beside terminally ill patients hours before they pass away. One theory is he has learned to detect the smell of biochemicals released by dying cells. On the bright side, Oscar napping beside a patient tends to give them peace, as this gives the staff plenty of time to notify family for something they couldn't predict, and even in the worst case scenario, the patient doesn't die alone.
  • There are scientific studies supporting this trope's existence.
  • Played for Laughs in one of The Weather Channel ad. A dog is barking at Jim Cantore and everyone else who recognizes him all freak out and run. Because he's a Doom Magnet, and his presence in your neighborhood would mean something bad's about to happen.
  • Dogs are being trained to detect Covid-19 infections by smell. If this proves to be a reliable screening method, it will hugely improve the odds of suppressing the infection's spread.

Alternative Title(s): Evil Detecting Cat, Evil Detecting Animal


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