Basically the power to discover other people's fears. Often necessary for a WhatDoTheyFearEpisode. This power can come in several forms: Type 1, Type 2 and Type 3

'''Type 1''' is the power to know what a person's fears are. For example, one could see a picture in your head or somesuch similar thing. One then has different options to use this info. This type does not necessarily include the ability to project those fears into people's heads and they may have to be exploited in a more normal way, such as dropping them in a snake pit or a sewer full of rats.

'''Type 2''' is the power to [[YourWorstNightmare bring a person's fears to life]] without actually having any knowledge about what those fears are, this power does not deliberately cause a person to believe they are, for example, vomiting worms, it's just the effect of the power on that particular person. It is sort of like infecting people with dread.

'''Type 3''' is the power to see a person's fear and/or show them their fears (if they have several). Control is near-absolute and often includes intensity and duration. A character with a Type Three power will usually have some kind of psychic or illusionary power to bring the fears to life.

It goes without saying that this is usually a [[BadPowersBadPeople bad guy power]].

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!!Examples:
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[[folder:Comic Books]]
* Dani Moonstar in ''NewMutants'' created illusions based on the target's worst fears, as did ''Comicbook/TeenTitans'' villain Phobia.
* A variation of Type 2 appeared in ''Creator/BrianMichaelBendis'' 's ''Comicbook/{{Alias}}''. In Volume Four, Jessica comes face-to-face with occasional ''{{Daredevil}}'' villain (and Jessica's archenemy) The Purple Man, whose body secretes chemical pheromones which, when inhaled or absorbed through the skin, allow him to control their actions by verbal suggestions. (The Purple Man, like ''SelfDemonstrating/TheJoker'', is aware that he exists in a comic book). He orders Jessica to imagine the most horrifying thing she can envision, which turns out to be the corpse of her boyfriend (Antman II) covered in ants lying in her bed. The Purple Man comments that he wonders what she is seeing, guesses "it doesn't work that way."
* In ''Franchise/{{Batman}}'', "The Scarecrow" has the power to discover and induce a person's greatest fear. (Ironically, poetic justice proves his ''own'' greatest fear turns out to be-- a fear of BATS!)
** This seems to be a major theme in ''Film/TheDarkKnightSaga'', especially in the first part, ''Film/BatmanBegins''.
** Another Batman villain, Cornelius Stirk, wanders into this territory as well. He's a telepath who can make other people see what he wants, which he uses to both make himself appear as someone they trust, and to prey on their fears.
* Trauma of ''[[Comicbook/AvengersTheInitiative Avengers: Initiative]]'' actually transforms into what his target fears, giving him whatever physical attributes and/or powers that go along with the new form. This combination of psychic powers and shapeshifting was considered a "holy grail" of mutant powers by [[{{Jerkass}} Gyrich]]. [[spoiler: Also, he's not really a mutant at all, but the [[HalfHumanHybrid half-human]] son of the dream demon Nightmare.]]
** It should be noted that this is imperfect--he went through four forms trying to find a weakness in TheIncredibleHulk (who, as it turns out, isn't afraid of anything), and got tossed into a parked car for his troubles.
* ''Comicbook/{{Gen 13}}'' villain Phobia was a creepy little girl with Type 3 powers.
* The Sinestro Corps of the Franchise/GreenLantern comics is based entirely on this concept. With their power rings they can create constructs of both their own fears and their victims'.
* The Nightmare spirits from IDW's ''[[ComicBook/MyLittlePonyFriendshipIsMagicIDW My Little Pony: Friendship is Magic]]'' comic inflict this upon our heroes when they try to rescue Rarity from their clutches. With ThePowerOfFriendship, Twilight Sparkle faces her fear of disappointing Princess Celestia and being dismissed as her student, Rainbow Dash her fear of losing the power of flight, Pinkie Pie her fear of being unable to make others happy, Fluttershy her fear of losing her way with animals, and Applejack her fear of letting down her family.
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[[folder:Film]]
* ''Film/{{Poltergeist}}''. According to their psychic medium consultant, the ghost causing the Freelings all the trouble has this ability.
-->'''Tangina''': Now clear your minds. It knows what scares you. It has from the very beginning. Don't give it any help. It knows too much already.
* Among Shang Tsung's powers in ''Film/MortalKombat'' is the ability to see into a person's soul and find out what that person fears most so he can use that fear against them, making this a Type 3 power.
* In ''WesternAnimation/RiseOfTheGuardians'', Pitch Black has this power- being the Nightmare King and the original Boogeyman, this is only expected.
* Freddy Krueger from the ''Franchise/ANightmareOnElmStreet'' franchise attacks people in their nightmares with their fears.
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[[folder:Literature]]
* Boggarts in the ''Literature/HarryPotter'' series take the form of a person's greatest fear, [[RequiredSecondaryPowers which means they have this power]].
* As do the phobophages in ''Literature/TheDresdenFiles''. Since their intended victim is at a horror movie convention, this results in {{Captain Ersatz}}en and {{Shout Out}}s aplenty.
* In the ''Literature/{{Belgariad}}''[='s=] prequels, Polgara's MindRape persuasion method is revealed to be this. It only failed once, because the target was on drugs (note that if she put much effort into it, she probably could have un-drugged him like Belgarath did in the prequel).
* Type 3 in ''Literature/NineteenEightyFour'', through sadistic government research on individuals and a "Ministry of Love" dedicated to custom torture.
* ''[[Literature/TheLastApprentice The Wardstone Chronicles]]'' includes a secondary character with the ability to do something called the Dread, which is a Type Two power.
* The ''BooksOfBayern'' include several characters, mostly antagonists, who are capable of knowing exactly what one fears (mainly things like public humiliation or loss of control, which are the things behind fears like acrophobia or arachnophobia) and also what a person wants, desires, or intends. Their power also gives them the ability to know precisely what to say in order to get what they want. Yeah. It's really no wonder they're mostly Bad Guys.
* The third book of ''Literature/{{Midnighters}}'' has a peculiar scene where [[spoiler:Rex]], the group's HalfHumanHybrid, attempts to intimidate a minor character. He somehow knows (without knowing how he knows) that said character is afraid of snakes, and his appearance and posture ''shift'' in just such a manner as to bring up thoughts of snakes, without changing blatantly enough to be obvious ShapeShifting.
* Amanda Reese of the ''{{Fingerprints}}'' series was a Type 1.
* Elva from the ''Literature/InheritanceCycle'' is a heroic (well, [[AntiHero kind of]]) example. She has the ability to sense a person's negative emotions, including fear.
* The Furies in the Franchise/StarTrek quadrilogy of the same name have this as their main weapon: a directed-energy beam that forces anyone who is hit by it to experience sheer terror.
* The titular Machine of ''Literature/GalaxyOfFear: The Nightmare Machine'' is a type 3, though some characters note with alarm that machines shouldn't be able to know what those specific fears are. [[spoiler: It's not a machine.]] The fears are amazingly powerful hallucinations, though not always internally consistent, and subject to YearInsideHourOutside.
** [[spoiler: Eppon]] in ''Army of Terror'' also has this ability.
* Polgara the Sorceress in {{David Eddings}}' Literature/{{Belgariad}} has been known to read a person's mind to discover their fears. Her use touches on a Type 3 in that she can also cause hallucinations, generally featuring those fears prominently.
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[[folder:Live Action TV]]
* Barbas, the Demon of Fear in ''Series/{{Charmed}}'', is a Type 1. Played by Billy Drago (John Bly from ''Series/TheAdventuresOfBriscoCountyJr'').
** He [[RecurringCharacter made several appearances throughout the duration of the show]], becoming important enough to have a GoodCounterpart shown in the MirrorUniverse episode. The sheer contrast between the personalities and actions of the two is rather hilarious.
* ''Series/StarTrekTheOriginalSeries'' episode "And The Children Shall Lead". Gorgon the Friendly Angel taught the children the power of learning another person's fears and using the fears to disable and control them. The kids caused Sulu to see swords surrounding the Enterprise so he wouldn't change course and used Uhura's fear of dying to prevent her from calling Starfleet Command.
* The alien monster in the ''Series/DoctorWho'' story ''The Mind of Evil'' attacked people with hallucinations of their worst fear.
** Similarly, the hotel in the ''God Complex.''
** The episode ''Frontier in Space'' has the Master using a "hypnosound" to induce this. Humans see the alien Draconians, while the Draconians see humans. Jo Grant sees a monster from one of her past adventures.
* In the ''Series/{{Haven}}'' episode "Fear and Loathing", Jackie Clark's Trouble is that anyone who looks into her eyes sees their greatest fears instead of her. She has no control over it and hates it. Her ability gets stolen by [[PowerParasite Ian Haskell]] twice.
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[[folder:Tabletop Games]]
* The DungeonsAndDragons arcane spells [[http://www.d20srd.org/srd/spells/phantasmalkiller.htm Phantasmal Killer]] and [[http://www.d20srd.org/srd/spells/weird.htm Weird]] are Type 2, as they do not require knowledge of their victim's worst fear in order for them to work.
** ''Warriors of Heaven'' has a nonlethal version of the first, 'Phantasmal Terror'. 'A Guide to the Ethereal Plane' introduces the unfortunate result of 'Phantasmal Killer' turning real, as illusions sometimes do there -- Fær, the monster who polymorphs into the victim's nightmare and kills by touch, but isn't resisted as easily as the original spell (it ''is'' for real this time).
** The Dream Larva is the [[EldritchAbomination manifestation of a god's nightmare]], with the ability to shape itself into anyone's greatest fear.
* In ''TabletopGame/ChangelingTheLost'' the first "clause" (read: skill) of the fleeting autumn contract allows a changeling to do this.
* In TabletopGame/InNomine, Calabim that serve the Demon Princess of Nightmares can see a person's worst fear.
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[[folder:Video Games]]
* Some of the ghosts from ''GhostMaster'' have the power to discover peoples unconscious or conscious fears. Often it's up to other ghosts to exploit those fears.
* In ''TheLegendOfSpyro: Eternal Night'', the final test to meet the Chronicler is to face the thing you fear the most. It's not explained exactly which Type it is, but it takes the one taking the trial's worst fear and makes an energy based version of that fear. In Spyro's case, [[spoiler: Cynder's evil adult form, as he was afraid of her being turned back into it.]]
** Cynder gets a Type 2 with her Fear element in ''Dawn of the Dragon''. It allows her to paralyze opponents with fear, either by letting out a [[MakeMeWannaShout sonic scream]] or blasting them with red energy spheres. Either way, the fear infecting is a secondary effect along side damage.
* Darth Phobos from ''Franchise/StarWars: VideoGame/TheForceUnleashed'' can use The Force to probe someone's mind to find their fears and create illusions of it. In her boss battle, she puts on a ShapeShifterGuiltTrip, as Starkiller's greatest fear is Juno Eclipse's death.
* Tatari from ''[[{{Tsukihime}} Melty Blood]]'' is a [[OurVampiresAreDifferent vampire that is repeatedly created from rumors]], and has the ability to [[RealityWarper manifest people's subconscious fears as reality]].
* Wizeman from NightsIntoDreams, being the god and creator of nightmare, is implied to have this power. He can also alter the dreams of visitors or create nightmarens in order to take advantage of these fears. He even uses it in the second game to steal Helen's red ideya by removing all light from her dream (Helen is deathly afraid of the dark).
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[[folder:Web Comics]]
* [[{{Walkyverse}} The Head Alien]] has a list of his enemies' fears and tries using it on Joe. However, since he mostly focuses on Joyce and Walky, his list isn't really accurate.
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[[folder:Web Original]]
* [[Wiki/SCPFoundation SCP]]-[[http://scp-wiki.wikidot.com/scp-825 825]] is a helmet that has this effect on its wearers, presenting them with increasingly horrific visions based on their worst fears.
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[[folder:Western Animation]]
* The Fear creature from ''WesternAnimation/ExtremeGhostbusters''.
* In ''[[LiloandStitchTheSeries Lilo and Stitch]]'', Experiment #300 has the ability to determine and mimic a person's greatest fear.
* Professor Screw-Eye from [[Film/WereBackADinosaursStory We're Back!]], has invented a radio that allows him to know what scares people.
* The Shadow of Fear from ''WesternAnimation/XiaolinShowdown'' is a rare form of both Type 1 and 2. In order to know what a person fears, one has to use it's first power to literally enter someone else's mind; the person using the Shadow of Fear also has some serious reality warping abilities in this state. Once a person has delved into victim's mind long enough to know what they fear, a person can then later use that knowledge to bring their fears to life in the real world.
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