[[quoteright:314:[[VanHelsing http://tvtropes.org/pmwiki/pub/images/NoReflectionVanHelsing.jpg]]]]
[[caption-width-right:314:''This'' is how you rig a limbo competition.]]

There are many things that go bump in the night, secure in the knowledge that their unholy powers can trick the human eye into blindness, allowing them to [[{{Masquerade}} live among and prey on humanity]] with impunity. But their supernatural (and at times [[AlwaysChaoticEvil inherently evil]]) nature means that no matter how complete the deception, they can never truly hide what they are. They may fool the mundane senses, but not the spiritual ones; inanimate objects, [[EvilDetectingDog animals]], [[OracularUrchin children]], TheEmpath or [[TouchedByVorlons spiritually touched]] people can sense and [[YouCanSeeMe see through]] the deception and cause a Glamour Failure. TheHunter and mundane heroes wise to these evil tells will be sure to use them to ferret out the villain; directors also love to work them into TheReveal when the creature's victim finally puts two and two together. More tragically, a hero under the effects of TheVirus will usually have the [[HeroicBSOD full emotional impact]] of it sink in when she [[TomatoInTheMirror can't see her reflection.]]

These flaws in their façade are usually mixed and matched. So [[OurMonstersAreDifferent your mileage may vary]] depending on the critter:
* No reflection (usually reserved for vampires and TheSoulless).
** Not appearing on film; digital cameras, voice recordings and telephone optional.
** True reflection (Fae or other glamour users will usually reflect their true image).
* Animals hate and distrust them (see EvilDetectingDog).
* Physical defect (usually for {{Shapeshifter}}s, [[CloningBlues Clones]], [[InvasionOfTheBodySnatchers Body Snatchers]], or {{Chest Monster}}s). See RedRightHand.
** Fairies and demons trying to pass for human were traditionally betrayed by their cloven hooves or tails, making this OlderThanPrint.
** Anyone who is [[DemonicPossession demonically possessed]] will usually grow tiny horns or [[TheCorruption slowly "mutate"]] to look like the demon possessing them.
* Mildly pronounced fangs (not huge, but big enough for the WolfMan and vampire to stand out; compare CuteLittleFangs).
* [[PointyEars Pointed Ears]]. A staple of vampires, fairies and Vulcans (though these last ones [[StrawVulcan aren't evil]], we promise [unless it's Evil Spock, but that's just a technicality]). For vampires, it's presumably to mimic a bat's large ears... or it could be done to up the HoYay factor.
* Unusual eyes: Red or yellow colored eyes, or vertical pupils.
** Variation (used in ''{{Discworld}}'', but based on earlier folklore): the eyes are the only part that cannot be disguised, and reveal the true nature of the being.
* No shadow (usually ghosts and {{Hologram}}s will lack these).
** Shadow moves on its own (a staple of vampires and ''really'' nasty critters; also of PeterPan).
** Shadow shows their true form (sometimes for shapeshifters).
* Silver burns (silver has reputed anti-evil properties, so it’s fair game for most creepy crawlies).
** Iron does the same (often for TheFairFolk).
*** Sometimes restricted to cold or wrought iron.
* Sunlight burns/weakens/[[{{Twilight}} makes them]] [[BishieSparkle sparkle]] (not restricted to vampires, any strongly evil or supernatural creature will react to sunlight like a marshmallow in an oven).
* [[ItBurns Holy objects burn/repel]] (pretty basic, anything holy aligned will repel evil, ''may'' be culture specific and/or depend on having a pure heart or strong faith).
* Cannot go someplaces either because they need to be invited, or the cannot cross some obstacle that would not hinder a human, such as running water, lines of salt or magic circles.
** Or the opposite, they are confined to a defined area (often for ghosts).

Some supernaturals will drop their glamour on purpose and reveal their GameFace or HissBeforeFleeing. When this happens on a large scale it's a BrokenMasquerade.

----
!!Examples

[[foldercontrol]]

[[folder:Anime & Manga]]
* Seras Victoria from the ''{{Hellsing}}'' anime burns herself with silver in the second episode.
** That would be one of Father Anderson's "Blessed Bayonets". It happens because she's a Vampire, and those are intended to kill them.
** She also burns herself to her own silver bullets, as well as cutlery (I think - it's been awhile since I saw the series).
* Subverted in the ''[[GhostInTheShellStandAloneComplex Ghost in the Shell: 2nd Gig]]'' episode "Trans Parent", in which Batou is convinced that a young girl can see through his thermoptic camouflage somehow. He's wrong -- [[spoiler:she's blind.]]
* The wolves in ''[[WolfsRain Wolf's Rain]]'' use some kind of glamour to appear human, but humans can occasionally see through it. There are also a couple of instances where the wolves look human but cast wolf shadows, though this only happens when humans aren't looking.
* {{The Count of Monte Cristo}} in ''{{Gankutsuou}}'' appears blurry and out-of-focus in photographs, and his voice cannot be heard in audio recordings.
* Nanami Jinnai in ''ElHazard'' gains the ability to see through illusions.
* On ''[=~Pokémon~=]'', the character Duplica had an inexperienced Ditto that could transform, but retained its own facial features, (such as they were). Her next appearance had a second, undersized Ditto, named Mini-Dit. This one could transform, matching everything but ''size''. This led to appearances by the likes of mini-Onix and mini-Ursaring.
* Medusa in ''Soul Eater'' has a tendency to form slit-like pupils when feeling particularly sinister, often accompanied with a SlasherSmile.
* Midway through ''ToAruMajutsuNoIndex'', Touma suddenly finds himself in a bizarre world where everyone's appearance has been swapped without anyone else noticing, leaving him the OnlySaneMan for much of the time. However, photographs are ''not'' changed from Touma's perspective (though even television broadcasts are). He identifies spellcaster responsible by how their appearance in person is the same as in a photo.
* A variation of this occurs early on in ''{{Harukanaru Toki no Naka de}}'' manga and TV anime. A female ghost, given a beautiful human form by the BigBad, seduces young men who come to visit her, devouring their souls. When [[{{Onmyodo}} Yasuaki]] is sent to investigate the case, she tries this tactic on him, only to be informed that [[ArtificialHuman he has no emotions]] that would allow him to appreciate her beauty, and therefore sees her just as what she really is (a skeleton). She does not take it well...
[[/folder]]

[[folder:Comics]]
* In the MarvelUniverse, there have been various ways over the years to detect the shapeshifting Skrulls, including superhuman senses, telepathy, magic, and various devices. Also, [[ThisWasHisTrueForm death]]. However, as of the ''Secret Invasion'' storyline, the Skrulls have figured out ways to trick telepaths, magic users, and super-senses, leaving technology (e.g. 3-D Man's special goggles) and improvised tactics (e.g. Ms. Marvel shooting a whole crowd with a low-level energy blast strong enough to knock down the humans and leave the Skrulls standing).
** And then Reed figures out a way to do reveal the Skrulls -anyway-. Guess he's not so [[ReedRichardsIsUseless useless]] after all.
* Komodo from ''Avengers: The Initiative'' must maintain some level of consciousness to keep her transformation, otherwise she reverts back to her true form. She does exactly this in one issue when she accidentally falls asleep in front of her teammate Hardball. Inverted in that she's an attractive young woman in her true form, while transformed she's a monstrous lizard...thing.
** But played straight in that [[spoiler:in her human form, she has no legs]].
*** Monstrous? She's awfully pretty in both forms.
* An interesting example is Mrs. Vashti, AKA 'Spell Syrin', one of the teachers of ''{{PS238}}'', and a former superhero. Rather than bother with official clothes, she just walks around in her spandex-tastic superhero outfit all the time, and uses Glamers to appear demurely-dressed to others. The reader, however, usually sees her as she really is, and a couple of mystically talented students have also demonstrated the ability to see through it. More interestingly, when mirrors appear, they show us what she appears like to others, in a direct inversion of the classic 'The mirror tells the truth' cases above.
** In that vein, Girl (Varied Number) from the ''Top Ten'' comic book series uses her color control over her android body to fake clothing. Too bad her commanding officer, a sentient dog, is color blind. Punching ensues.
[[/folder]]

[[folder:Films]]
* In John Carpenter's ''TheyLive'' (1988), aliens use a mind-controlling satellite signal to appear human, cloaking themselves from the eyes of Mankind while they take over governments and corporations. A resistance movement forms when someone creates [[CoolShades special sunglasses]] that can filter out the signal before it reaches the brain and allows the wearer to see the aliens as they truly are.
* ''TheShadow'' (1994) with Alec Baldwin as Lamont Cranston a.k.a. the mysterious Shadow, the titular character of this movie screen comic book adaption. His powers of deception, mind control and telekinesis are clearly [[PsychicPowers psychic]], the result of a TrainingFromHell by an ancient mysterious Asian mentor. Only two people can see through his hypnotic deception: his arch-enemy who has similar mental powers (and who can hide whole buildings from the eyes of passers-by), and the [[MadScientistsBeautifulDaughter professor's blonde daughter]] who is a latent psychic herself and who catches a glimpse of The Shadow when she meets Cranston.
* In ''Film/XMen'', Mystique's shapeshifting isn't quite perfect. Her eyes flare yellow if she loses her concentration, for example, and she can't quite mimic the smell of others (making her particularly vulnerable to Wolverine's sense of smell).
* The T-1000 in ''{{Terminator}} 2'' could imitate anything it touched, within certain limitations. However, after being frozen and shattered, its mimicking technology got a bit... twitchy. Beyond that, your only clues are his precise movements from the UncannyValley Acting School, and a BluffTheImpostor moment when he's imitating John's foster mother.
* In ''Phantom of the Paradise'', Swan's lackeys always make sure that he's never photographed or filmed. It's revealed that [[spoiler:years ago he made a DealWithTheDevil that allows him to never age; part of the price is that this trope applies to any pictures/film taken of him since the pact was originally made (and videotaped -- the tape is his SoulJar).]]
* In the ''{{Blade}}'' movies, the Glamour Failure ended up being needed. If you were a certain vampire's pet, you got a tattoo so other vampires knew not to eat you. This helps (and oddly hinders) Blade. And relatedly, despite getting all the good bits of vampire powers in his origin (durabillity mostly) he cannot detect if his adversary is a human with fake pointy teeth. This also comes back to bite him on the ass (pun intended).
* The page image from ''VanHelsing'' shows one of the common ways in which vampires can experience this -- lacking a reflection in a mirror.
** This was parodied in ''Dracula: Dead and Loving It'', where a big dance scene ends up being ridiculous when seen in a mirror, particularly when Dracula is spinning the woman in the air.
*** Well, to be fair she was doing quite well on her own
* In the 1986 remake of ''TheFly'', Seth Brundle realizes just how badly he has already been transformed when the computerized teleportation pods refuse to recognize his voice.
* In ''TheLittleMermaid'', Ursula, in the guise of a beautiful woman named Vanessa, is found out when Scuttle sees her true form reflected in a mirror.
** Eric's dog Max also [[{{EvilDetectingDog}} hates Vanessa and growls at her when she's near]].
*''BladeRunner'' replicants are identical to humans. The only reliable way to detect them is the Voight-Kampff test which monitors answers and subtle physical response to emotional questions.
** [[FridgeLogic Apparently they can't be detected by the fact that they're immune to both extreme heat and extreme cold]].
*** That only really matters if you don't mind a test which kills the innocent while leaving the replicants themselves unharmed...
** And apparently even though every scale of an artificial snake has the manufacturer's serial number on them, no-one thought about putting anything similar to much more dangerous humanoid replicants.

[[/folder]]

[[folder:Literature]]
* The {{Discworld}} gods, despite their reality-altering powers, cannot change their eyes. Said eyes always reveal something about their true nature.
** In the novel ''Reaper Man'', there's a scene where a child sees [[TheGrimReaper Death]] in his true form as a skeleton man, whereas Death is able to make adults see him as human (or they at least convince themselves they aren't seeing a skeleton).
** Blacksmiths (even Death's horse needs shoeing) use blindfolds when the time comes. Knowing Death is hanging around is a pretty scary proposition.
** In ''Lords and Ladies'', those who get close enough to [[TheFairFolk the elves]] or who are wearing or carrying enough iron can see through the glamour they cast and notice that they look... well, ''alien''. Dwarfs, trolls and animals (such as everyone's favourite sentient orangutan, The Librarian) get this ability for free. Dwarfs and trolls go into "crush, kill, destroy" mode when seeing said elves.
*** With the dwarves it probably has more to do with the always-present armor and helmet than an in-born ability.
** The Glamours of the elves as well as of Death rely on a forced augmentation of the normal human WeirdnessCensor: they convince the person that they cannot possibly be seeing what they are, and so the brain makes up imagery that fits this impression. People who have a reason to see through the illusion (such as the dwarves with their intense hatred for elves) or who already know what they're looking at aren't fooled.
** With the Elves it's a different matter, actually. While Death and other things that's presence people can't accept, such as talking dogs simply take advantage of people's desire not to see things that disturb them, the Glamour of the Elves is an active power they must concentrate on to keep it working. If you knock an elf unconscious, the Glamour vanishes, but if Death loses his wits, due to being heavily intoxicated, for example, people still won't recognise him for what he is.
* In Nathaniel Hawthorne's story ''Feathertop'', the title character is a scarecrow with a pumpkin for a head who, due to a witch's spell, is made to appear as an elegant nobleman. When he first goes into public, adults are praising him, but it's mentioned that a small child "keeps babbling about a pumpkin." Later, Feathertop sees himself in a mirror and realizes he's not human and can no longer live with himself.
* In the ''{{Chronicles of Thomas Covenant}}'', no shapeshifter can change [[RedRightHand their eyes, which may be highly unnatural in color.]] On that basis, occasional GlamourFailure is not that surprising.
* In Robert Blake's story "Shadow from the Steeple", which is a sequel to H.P Lovecraft's "Haunter in the Dark", the protagonists confronts the man he believes to be possessed by the god Nyarlatotep, noting that his skin has turned darker. The man explains this has been caused by exposure to radiation (he was a nuclear physicist), but when the protagonists doesn't believe him, he turns off the lights, causing his entire body to glow with unnatural light, and causing the protagonists to die of heart attack.
* A variation of this shows up in Mike Resnick's science fiction novel ''Santiago'', although that is more due to a lack of knowledge on the villain's part. In order to kill the bounty hunter Sebastian Nightingale "Songbird" Cain, the assassin Altair of Altair somehow makes him hallucinate that he is back on his home planet of Sylaria being asked by someone he cared about to help her across a brook (as a lure to get Cain close enough to Altair for her to stab him). At the last moment, he shoots her and tells her corpse, "There aren't any brooks on Sylaria." Apparently Altair DidNotDoTheResearch.
* In DanAbnett's ''Brothers of the Snake'', a squad of marines finds themselves fighting foes that can ''only'' be seen with the naked eye; all their equipment will not recognize them. They bare their faces and win, though several die because of the vulnerability. Later, a Chaos daemon infiltrates a Chapter House. After one Marine recognizes it and kills its host, it escapes, but a second one manages to recognize it. (It also manages to make the rest of the House believe that the first Marine was raving in his cell, but the second one manages to see that in fact, the man is sitting there quietly, and talks with him.)
* In StephenKing's story "The Ten O'Clock People" (found in ''Nightmares & Dreamscapes''), only very light smokers can see the "batpeople" who are steadily taking over. Non-smokers and heavier smokers alike simply see humans where the titular group sees the monsters.
* There isn't any real way to tell that Dr. Jekyll and Mr. Hyde are the same person (other than ItWasHisSled anyway), but they do have the same handwriting in the original novel.
* Although in ''{{Jonathan Strange and Mr Norrell}}'', TheFairFolk are TheBeautifulPeople, in some tales from the story collection set in the same universe ''The Ladies of Grace Adieu and Other Stories'', they and the other creatures they consort with are shown as actually being monstrous and their fabulous palaces are similarly an illusion hiding squalor.
** There are subtle hints in the few descriptions of Lost-hope in ''JonathanStrangeAndMrNorrell'', for example, there are tapestries made of skin. It's never commented on and is probably quickly forgotten by the average reader.
* Several stories in C.B. Colby's ''Strangely Enough'' feature animals detecting the unusual and supernatural. "Black Knight of Canterbury" has a dog detecting the passing of a ghostly knight, and in "The Frightened Dog" the title animal detects the approach of a weird threat before the humans he's with do.
-->'''Colby:''' Perhaps it is true that dogs can see what we cannot.
* ''Rod Serling's TheTwilightZone'' anthology, story "The Avenging Ghost". A Great Dane named Duke is able to detect and see the ghost of his dead master before the humans with him can.
* In Carrie Vaughn's ''KittyNorville'' series, dogs can detect lycanthropes. This troper cannot remember whether or not the same holds true for vampires. In either case, said dogs are not of the [[EvilDetectingDog evil detecting variety]], since they go berserk even in the presence of the titular heroine.
* The main character of ''Peter Schlemihls wundersame Geschichte ("Peter Schlemihl's Remarkable Story")'' [[DealWithTheDevil sells his shadow]] in exchange for great wealth, but is shunned by the rest of society for not having a shadow.
* Rather inverted in ''[[TheObsidianTrilogy The Outstretched Shadow]]'' by MercedesLackey and James Mallory. In their true form the demonic creatures known as [[NamesToRunAwayFromReallyFast the Endarkened]] possess red skin, horns, and [[EyesOfGold catlike yellow eyes]]. Neither the Endarkened or thier works[=/=]creatures[=/=]spells can withstand the touch of a Unicorn even were one [[VirginPower chaste and celibate]] enough for a unicorn to let touch it without trying to kill them. So when a woman with red skin, horns, and catlike yellow eyes is cowering away from you ''against a unicorn you personally know'' (who is sitting there rather calmly and looks more annoyed with you than her) then it is clear [[{{Understatement}} Something Strange Is Going On]].
[[/folder]]

[[folder:Live Action TV]]
* ''BattlestarGalactica'': Humanoid Cylons are very difficult to detect in isolation, but once more than a few get together it gets much easier as there are many copies, but only twelve "models". Their very existence is sniffed out this way by Helo in Season 1, and again by Kendra Shaw in the movie. [[spoiler:Although five models exist as individuals without additional copies.]]
* Several villains on ''{{Are You Afraid of the Dark}}?'':
** ''The Tale of the Mystical Mirror'': A woman who killed young girls in a ritual to keep herself eternally young and beautiful looked like an old hag (and so did her portraits) in mirrors. Hence why one girl wondered while visiting her house, "How can you be so vain and not have a mirror in your bathroom?"
*** Clearly taken from the folklore surrounding Transylvanian (Romanian) Countess Erzebet (Elizabeth) Bathory.
** ''The Tale of the Captured Souls'': A boy who stole people's youth to make him young forever looked like an old man in mirrors, pictures, and on video camera and was thus alarmingly camera shy.
*** Taken from Oscar Wilde's ''A Picture of Dorian Gray''.
* Parodied on the US version of ''TheOffice''. Jim is attacked by a bat and spends the rest of the episode faking vampire symptoms (garlic aversion, repulsion at Karen's cross, etc.). A dangerous game, knowing Dwight.
* The ''{{Smallville}}'' version of Bizarro looks exactly like Clark unless he's weakened or, later, exposed to sunlight, in which case his face will briefly flicker into a broken-glass-ish looking form that calls to mind the earliest comic book versions of the character.
** Incidentally, the GenreSavvy would be able to tell simply because his wardrobe is in opposite colors to the real Clark Kent. [[TooDumbToLive Nobody fits that description, though]].
* A heroic example: Sam Beckett in ''QuantumLeap'' can be seen as he really is by the very young and animals, and sometimes by the insane, psychics, or people whose brain patterns are similar to his own. This also applies to his friend Al, who appears as a hologram that is normally invisible to others than Sam.
** Although due to real-life technical limitations, Al's hologramatic appearance sometimes casts shadows, his cigar smoke is affected by wind, his cigar smoke is visible despite the established rule that only things Al touches can be seen, etc.
* The Latino Soap Opera ''La Mujer en el Espejo'' ("The Woman in the Mirror") is about a homely woman who finds a magic mirror that gives her a beautiful appearance -- but her reflection still looks ugly.
* ''Buffy the Vampire Slayer''. Buffy is supposed to be able to sense vampires magically, but this seems to be one of the Slayer powers that just did not manage to cross over. She still figures out two or three vamps because their ''fashion sense'' stalls at the point of time they, the vampires, first died. Dated clothes trumps weirdo magic-sense.
** Faith mentioned being able to tell if Angel was anywhere in a building, so it works pretty well for her. Apparently Buffy just has the sensitivity of a brick given the number of times vampires have been able to get right up to her without being noticed.
***Note that this ability may have been specifically honed by Faith after she accidentally killed a human she mistook for a vampire. Buffy, being able to rely on her other instincts to spot vampires, simply hasn't bothered.
* The Rakshasa are featured in ''{{Kolchak the Night Stalker}}''. This variation could appear as someone its victim trusted and/or loved; it could be repelled by the Swastika, which was a sacred symbol long before Nazi Germany co-opted it. This version was the direct inspiration for the ''D&D'' version, being vulnerable to a blessed crossbow bolt.
* The first episode of ''{{Merlin}}'' uses the mirror variant with a vengeful crone who kills an esteemed guest of Camelot and takes her form.
* Used several times in ''{{Supernatural}}''. Mainly the true reflection variant (such as the Changelings, or the Siren). Occasionally, they'll thrown in the physical defect variant (the "flip-to-silver" eyes for the shapeshifters, a retractable layer of fangs for vampires.) But since most of the characters in the show ''hunt'' these nasties, they also have several tests, just in case. For starters, iron and [[ItBurns holy water]] are pretty good indicators that a baddie is about.
** Bobby actually uses these tests on Dean after the latter [[spoiler: gets out of Hell]], just to make sure Dean is, in fact, Dean.
* ''[[StarTrekDeepSpaceNine Star Trek Deep Space 9]]'''s brand of Changelings, the Founders, are liquid beings that can perfectly mimic any object (though some, like Odo, can't get the faces right). In later years, the only way for the Federation to scope out a Founder is through blood tests, as any material drawn from a changeling reverts back to its own natural liquid state (that looks very different from blood).
* ''TheXFiles'' episode "The Unnatural" is about an alien who falls in love with baseball, taking on the form of a Negro player in 1947 Roswell. At one stage while he's asleep another character sees his true [[TheGreys Grey alien face]] reflected in the window of the bus they're traveling on. The image disappears when he wakes up.
[[/folder]]

[[folder:Mythology]]
* In Japanese mythology, a Kitsune's (fox's) human-disguise is often revealed because a Kitsune cannot hide its real eyes in reflections.
** Also, a young, inexperienced, drunk, or just plain careless kitsune may accidentally reveal its fox ears or tail(s); this seems to show up especially often in anime. This seems to imply that the ears and tail are the hardest body parts for a kitsune to transform, though this troper has yet to find any work in which this is explicitly stated.
*** The tails being difficult to transform makes sense, but maybe the ears are just easy to forget about?
** Kitsune are also said to be incapable of saying "moshi moshi", which lead to the phrase being used as a greeting. It is still a typical way to answer the phone in Japan.
* [[NorseMythology Odin]] gave up one of his eyes for wisdom. He usually is unable to fully conceal this.
* In Jewish, Russian, and some other folktale traditions, demons and vampires had bird feet which they couldn't conceal no matter what form they took.
* There is a story about the Walsh Saint Collen who entered a fairy castle at the behest of its king. He was invited to a banquet there, but wisely refused to eat, remarking that the food was only tree leaves. When the king asked what he thought of the red and blue garments worn by the castle servants, Collen said that the red signified the side being burnt and the blue signified the side being frozen. He then poured holy water on the ground, causing the entire castle to vanish.
[[/folder]]

[[folder:Tabletop Games]]
* In ''[=~Changeling: The Lost~=]'', the Mask that disguises changelings as mortals always shows some small hint of their true nature and appearance. This gets worse as they become more powerful -- the most powerful, although still human in appearance, look decidedly ''off'', and are unlikely to be able to go anywhere without drawing unwanted attention. Also, certain people can sometimes see through the Mask -- the insane, those who are high, [[TomatoInTheMirror fetches]], very young children, people with certain forms of brain damage... it's not a sure thing, though. Furthermore, a changeling's shadow '''always''' shows hints of their true nature -- if you were turned into a mountain goat, your shadow's going to show horns, even if you strengthen the Mask to the point that even other Changelings can't see through it, or use Contracts (Fae magic) to appear as something or someone else entirely. Fortunately, the shadow only looks 'off' to other fae or creatures that can see through the Mask, not to everyone in general.
** In ''[=~Promethean: The Created~=]'', Prometheans appear human, but other people can sense that there's something ''wrong'' about them on a deep, fundamental level. This feeling can build over time until the point where a lynch mob is forming. It gets worse when a Promethean uses their innate powers around another person, because then the glamour fails utterly and they can see the Promethean in their true form - an animated corpse.
* The tiger-like Rakshasa in ''[[DungeonsAndDragons Dungeons & Dragons]]'' are demonic shapeshifters (derived from Indian folklore) who can disguise themselves as any humanoid creature, with the caveat that their hands are always facing the wrong way on their wrists.
**This has varried over the years from the hands being upsidedown to the palms being on the wrong side. i.e. the left and right hands were switched. Another version from the spinoff parody Dungeon Hack described their hands as being upsidedown and switched, so that the palms faced inward, but the thumbs were on the bottom and the pinkies on top. This is the only version where the palms faced inward.
* ''D&D'' also brings us the "Changelings", a sort of Doppleganger / Human hybrid who can appear like any sort of humanoid they wish. However, a ''true seeing'' spell will easily reveal their true form. For the record, they're grey, with gangly and slightly off proportion limbs, white eyes, and only the slightest indication of a nose and mouth. [[ThisWasHisTrueForm They also turn back if killed, of course]].
** Infant changelings are also unable to maintain a fake appearance while asleep, returning to their true form. There're also certain size and mass limitations for a changeling's tranformation.
** An article on Changelings in one ''{{Eberron}}'' sourcebook dedicated an entire section to "ways to spot a Changeling". The top causes of GlamourFailure are [[OohMeAccentsSlipping an incorrect accent]], incorrect clothing (the body might transform, but the clothes do not) and a lack of knowledge on local customs.
* In ''{{Exalted}}'', the Lunar Exalted are shapeshifters extraordinaire, but each one possesses a single animal feature -- its Tell -- that remains consistent regardless of what form it takes. The Tell is usually fairly subtle, such as an oddly-colored patch of hair or strange-looking eyes, but it does allow anyone who knows what he's looking for to identify the Lunar.
** Also in ''Exalted'', Solars have a awareness charm that make them ignore glamour as if it were not there.
* In the ''{{Warhammer 40000}}'' universe, daemonhosts (a daemon [[SealedEvilInACan sealed in the body of a human]] by means of occult rituals and symbols) generally resemble the person whose body they're possessing, but with distinct physical changes that identify them for what they are. For example, in the final ''{{Eisenhorn}}'' novel ''Hereticus'', Inquisitor Eisenhorn notes that while the daemon Cherubael has made all the usual physical alterations to its host body - small horns, glossy golden skin, blank eyes, and claws - the daemonhost still bears a chilling resemblance to [[spoiler:his old friend Godwyn Fischig]].
** Another ''[=WH40k=]'' example: in the ''GauntsGhosts'' novel ''Ghostmaker'', [[spoiler:an Eldar Farseer is manipulating the memories and perceptions of the Tanith First and Only, making them believe that they are back on their doomed homeworld, fighting for its survival]]. The illusion isn't perfect, however, as several characters get the sense that something is wrong, and eventually the glamour fails entirely when [[spoiler: mildly psychic teenager Brin Milo looks at a disguised Eldar warrior through the appropriately-named "Mad" Larkin's sniper scope, revealing that the tall, thin "Tanith" with white and red hair is in fact a [[SuperSoldier Dire Avenger Aspect Warrior]]]].
*** Gee, you'd think maybe the 8' 8" Farseer would have been a bit of a tip off. Or the fact that the Dire Avengers weren't even pretending to act human
* Many of the {{Glamour Failure}}s in ''{{Deadlands}}'' are exactly what one would expect from a series were AllMythsAreTrue: silver repels even human-form werewolves, and so on. The series' most unique form of [[CameBackWrong revenant]], the Harrowed, bear most extensive discussion: they carry the [[EvilSmellsBad smell of death]] everywhere they go, have a distinctly [[EvilAlbino pale complexion]], keep a [[RedRightHand scar from their cause of death]], and are prone to [[EvilDetectingDog setting off]] nearby wildlife. If a lot of their giveaways make them sound like evil incarnate, it's worth remembering that even the [[AntiHero nice]] [[HeroicWillpower ones]] have a JekyllAndHyde complex.
[[/folder]]

[[folder:Video Games]]
* In ''{{The Legend of Zelda}}: A Link to the Past'', you find a girl trapped in one of the dungeons who asks you to lead her out, but if you do so she tells you not to go out that way. You have to lead the "girl" into a room with bright sunlight coming in, which reveals her to be the boss Blind.
* In ''PhantasyStarOnline'', in the Seabed area, there are robot enemies that are usually invisible. However, you can see their reflections in the water and reflective surfaces that are usually common throughout the area, making it possible to attack them. Also, using a lightning spell will short out the invisibility for some time.
* Reversed in one of the possible quests in the video/PC game ''Darkstone''. A witch has cursed the women of a local village to turn to stone if they ever become more beautiful than she is. Since she looks to be about three million years old, all the women are statuary. Your character must visit the local dungeon and find a perfectly normal-looking man who is convinced that he's ugly as sin, so has come down to find the Fountain of Youth in order to hopefully fix the problem. Turns out that his real problem is that he's been using something called the Mirror of Lies, which makes beautiful people appear ugly and vice-versa. After getting it from him in exchange for a normal mirror, your character gives the Mirror of Lies to the witch, fooling her into believing that she's young and gorgeous again, so she releases the spell on the village.
* Bart Simpson can see through the aliens disguises with X-ray specs in ''Bart Vs. The Space Mutants''.
* In ''SuperMarioRPG: Legend of the Seven Stars'', the fake residents of Seaside Town look sort of like real mushroom people, except they have metallic colors and don't move like a normal mushroom person should.
* In ''DevilMayCry'', when Dante and Vergil's father Sparda took human form, his shadow remained shaped like a demon.
[[/folder]]

[[folder:Web Comics]]
* The protagonist of ''[[http://www.magickitsune.com Fox Tails]]'', Keen Kotaru, possesses a so-far unexplained ability to see through the Glamours of the various animal-spirits that are otherwise maintaining a {{Masquerade}} in our world. His ability to thus notice the remaining animal features of transformed spirits is what drives the plot, and allows him to effectively fight the evil spirits...
* In ''ErrantStory'', the Elven Rangers who move around the world of men in search of 'Errants' (half-elves who frequently become psychotic) often uses glamours to disguise their elven nature. At one point, however, a young child can see through it, though her mother dismisses it...
* In ''{{Dan and Mabs Furry Adventures}}'', the Cubi all possess powerful shape-shifting abilities, which obviously comes in handy [[HornyDevils for many things]]. However, they all have a single "marking" on them that they cannot change -- and which also shows what clan they belong to. If you manage to spot such a mark, and happen to know what they mean, you'll both know that you're actually facing a Cubi -- and ''usually'' whether it's the kind that feasts on pain, terror and suffering, or the kind that feeds on lust, joy and happiness. Very handy for determining what your next response should be, really.
** Although make-up or clothing can conceal them.
* In ''GunnerkriggCourt'', certain individuals are living Glamour Failure, who unconsciously dispel illusions by their very presence. Antimony is one such person, as her encounter with the ghost in the hospital showed.
* ''LastResort'' uses the "Dead Eyes" of the Djinn-si as a quick tell-tale for identifying most Dead Inside, and it's also the only part of Alice's body that can't be changed by shapeshifting.
** For [[OurVampiresAreDifferent Vampire Djinn-si]], though, it's just part of their GameFace (though if you piss one off enough, you can still cause an AccidentalReveal).
[[/folder]]

[[folder:Web Original]]
* The webnovel ''{{John Dies at the End}}'' tells the story of two college dropouts who discover and fight an otherworldly invasion after a chance run-in with a supernatural drug changes their perceptions forever. As a result, they see a lot of freaky stuff [[InvisibleToNormals invisible to everyone else]], but they also gain a lot of experience identifying subtle clues that ordinary people could notice if they paid attention. They learn mirrors can be used to circumvent certain illusions, religious symbols can be used to flush out and ward off evil, and household pets can be used to detect and identify paranormal beings.
[[/folder]]

[[folder:Western Animation]]
* ''[[{{Ptitlemxi508a6}} Avatar: The Last Airbender]]'': Joo Dee, the kids' [[ObstructiveBureaucrat obstructive]] StepfordSmiler minder who follows them around Ba Sing Se is driven bonkers by them poking holes in her [[TheGovernment government]] cover story. She's promptly replaced by a new Joo Dee, and it's later revealed that there's [[SendInTheClones a lot more where that one came from]].
* Hilariously done on the children's show ''CountDuckula'' where the titular duck decides to redecorate the castle and one decorator hired does the place up in all windows. Of course, since the duck is a vampire, he can't see himself in any of them.
* ''BatmanBeyond'': Whenever Derek Powers got angry, which was frequently, his powers would flare up and start to burn through his artificial skin, revealing that of the [[ILoveNuclearPower radioactive]], [[PowerGlows glowing]] villain Blight. Actively using his powers for even a few seconds will completely shatter it, requiring him to have new skin grafted on. His inability to keep his skin on through the events of any given workday actually makes him a case of BlessedWithSuck.
** This worsens as he undergoes a [[VillainousBreakdown figurative meltdown]], followed by a literal [[SuperPowerMeltdown meltdown]] which left him apparently KilledOffForReal.
* In ''{{The Grim Adventures of Billy and Mandy}}'', whenever Nergal Junior transformed, he always retained his green eyes, glasses, and fangs.
* In ''SamuraiJack'', anything Aku transforms into has the same black/green/red color scheme he does, and his true form shows up in reflections.
** He's clearly aware of this, as he doesn't use the power to try fooling Jack.
** Except for that one time he disguised himself as a beautiful woman and managed to fool Jack all the way till the end of the episode, at which point it was too late as Aku managed to destroy the MacGuffin Jack had spent the episode trying to locate.
* While not a person, an episode of ''JusticeLeague Unlimited'' has Hawkgirl discover a mine on a faraway planet was fake (and, thus, a trap) when the holographic shadows it cast from her [[PowerGlows glowing mace]] didn't follow the same direction of the other shadows the mace cast.
** Earlier, a spell cast on Superman and Wonder Woman to make each think that the other was a demon could only be broken once they saw the other's reflection. The problem was that, once Superman saw what was going on, he felt unable to fight Wonder Woman, and thus had to take a beating until Wonder Woman saw it too.
** And there is the whole ''In Blackest Night'' episode, where John is tried for destroying a planet. The others notice the planet's sattelite is stil orbiting it, find the holoprojector, and blast it apart, causing the planet to reappear right in front of the judges.
* In ''CodeLyoko'', [=XANAfied=] people and Polymorphic Specters can be recognized by their [[MindControlEyes pupils turning into]] [[HellishPupils "Eye of XANA" symbols]], or by their tendency of getting blurry with "static" from time to time. They can usually suppress this long enough to force a SpotTheImposter Check, though.
* On ''{{X-Men Evolution}}'', Kurt's image inducer. Given that it really only needs the settings "off" and "on" was there really the need to give it so many options and make the off button so incredibly easy to press by accident?
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