Your Worst Nightmare

Someone or something is tormenting our heroes in their sleep, be it one of their regular menaces or something new. At best, the recurring nightmares are causing them sleepless nights and impairing their performance in the real world. At worst, they find that any injuries in the dream world carry over to the real world and their lives are in serious danger. Either way, the protagonists must find out how to stop their night-time tormentors.

Subtrope of Talking in Your Dreams. May be mistaken for Bad Dreams, Dreaming of Things to Come, Dream Spying, or Dreaming of Times Gone By. Indeed, those tropes can be used by the attackers.

See also Primal Fear, Nightmare Dreams, Room 101. Not to be mistaken for Your Favorite, unless you are a Nightmare Fetishist.

Not to be confused with I'm Your Worst Nightmare (which is just the phrase).

Anime

 * This is the ability of the Death 13 stand in Jo Jos Bizarre Adventure. To make matters worse for Jotaro and co., Kakyoin is the only one who can remember what happens inside the dream world. He eventually figures out that the user controlling the stand is the baby that's travelling with them, making things more difficult. He had to carve the information into his arm in the dream which transferred onto his real body.
 * In part of Nightmare Inspector, Tsukishiro, Hiruko's rival baku, alters people's dreams to make them more terrifying, and tastier to eat. Mind you, most of them were already having nightmares already, but Tsukishiro made them much worse.
 * In a side comic to Star Blazers/Space Battleship Yamato, Desslok's exiled wife and daughter have the power to psychically torment people, which they usually do when their victims are asleep. Their usual modus operandi is to make them hallucinate family members begging for help and warning the Star Force of danger, though Nova saw three-fingered hands grabbing her.

Comics

 * Ashley gets up to a lot of this in  in Hack Slash. Unfortunately for him,.
 * Batman villain Scarecrow has used just about every possible variation of this trope in his lengthy career. Sometimes his involvement is left as a surprise, and his motives vary from revenge to simply studying the effects of fear.
 * When Scarecrow uses his fear toxin on The Joker, though, he accomplishes nothing at all. The Joker just finds fear (even his own) to be funny.

Fanfic

 * Ultimate Sleepwalker: The New Dreams has a rather gruesome variant with Psyko, whose madness beams force anyone affected by them to constantly relive their worst nightmares over and over again. What makes this stand out is that Psyko not only commits Mind Rape on his victims, but he can also use their bodies as People Puppets in making them do his bidding even while they're hallucinating. Oh, and he can also do all this when you're wide awake.
 * Deadlock does this to Spyro and Cynder in The Legend OF Spyro: A New Dawn during the "Restless Night" chapter. She makes them both experience rather frightening nightmares, Cynder reliving killing her mother as Dark Cynder and Spyro dreaming he turned into Malefor. Cynder's is worse because she sees the blood of the dragons she killed as Dark Cynder dripping from her claws.

Film

 * The A Nightmare On Elm Street movies are probably the best example of this trope, with hapless teenagers being tormented and slaughtered by the dream-walking, One Liner-spouting psycho-killer Freddy Krueger.
 * The Simpsons parodied the series in a Halloween special episode in which the children of Springfield were terrorized in their nightmares by the deceased Groundskeeper Willie. After Bart, Lisa and (mainly) Maggie defeat him in a dream, they wake up and are confronted by a very much alive Willie, who makes scary faces for a few seconds, until he's forced to turn around and chase the bus he just arrived in, shouting "Wait! Wait! I left my gun on the seat!"
 * "Wait here, please."
 * In Dreamscape (1984), psychic Tommy Ray Glatman can kill people by inserting himself into their dreams and scaring them to death. Eventually the Hero learns how to do it too and kills Glatman and his boss the same way.
 * In Embrace of the Vampire, the vampire visits a college freshman in her dreams as a way to seduce her.

Literature

 * In Animorphs book 6, Jake had an unexplained vision of a thing with a Big Red Eye. In the much-anticipated book 26, it was revealed that since then, he'd been having nightmares that replicated the experience perfectly, except that at the end, the BRE said "Soon." And then, the BRE was finally identified as being that universe's closest analogue to Satan.
 * In the Discworld novel Hogfather, a band of intruders in the home of  are menaced (and in many cases, killed) by a number of scary things from their childhood. One is literally swallowed up by darkness, another is devoured by a wardrobe with a creepy face in the woodwork, a third is chased off (and presumably killed) by a "Scissor Man" (read: a man made of scissors who threatens children that suck their thumbs), a fourth is attacked by an exaggerated version of a bully they knew in school, and one dies of a heart attack after being menaced by a giant version of his domineering, abusive mother.
 * The Chronicles of Narnia: The Voyage of the Dawn Treader included an area of ocean known as the Dark Island "where dreams come true". In this case, "dreams" meant "dreams" not "wishes" or "daydreams". And "dreams" includes "nightmares".
 * It was so awful that the lord who had spent several years there begged King Caspian to swear that he would never permit anybody to ask him about his experiences.
 * That was retconned in recent editions claiming to restore the "original text" intended by C.S. Lewis. That lord now asks to never be returned to the island (the point being that in this text, unlike the other, it's clear that the island still exists).
 * In the movie, the Dark Island terrorizes the people of the ocean and is apparently pure evil. It tempts and creates the fears of those who want to destroy it.
 * In Grave Peril, book three of the Dresden Files, a ghost torments (and occasionally drives insane) its victims in their sleep. It eats Harry alive.
 * This is the power of the boggart species in Harry Potter. The fears seen range from mundane (Hermione being told off by a phantom teacher for failing a test) to poignant (Molly Weasley seeing a vision of her dead sons). Harry's worst nightmare, interestingly, is the Dementor - a creature that spreads fear by its very presence, meaning his worst fear is fear itself.
 * HP Lovecraft set a whole series of stories (tied to the Cthulhu Mythos) in the Dreamlands, or some such name. It's no surprise he used this trope, in one story where a tale is transmitted -- somehow -- to the narrator concerning a man who cannot wake up, and is chased through his dreams by Eldritch Abominations. The narrator concludes by stating that he is afraid of what he might find if he visits the address mentioned in the story.
 * In Through the Ice by Piers Anthony and Robert Kornwise, the heroes were magically attacked with dreams of their respective worst fears. After several failed attempts to defend themselves, the only successful method was to "yield to it," make the nightmares worse, and then (with the help of their telepathic team-member) hurl them back at the sender.
 * In the Wheel of Time series, this is the effect of dreams that touch Tel'aran'rhiod. Just brushing against it while dreaming of a dangerous experience can result in bruises or scrapes; actually being inside it when you dream of dying will kill you. Fortunately, few people are ever fully inside without a special power, but sometimes you can be sucked in by someone who has the ability to do so. One poor fellow is made to simply fade away into nothing.
 * Occurs in the original Dragonlance Chronicles series when the Heroes of the Lance penetrate the Nightmare of Silvanesti. Most of the heroes perish in ways that would arguably reflect their worst fears-Sturm dies a coward, Flint dies when his old age catches up to him, Tika dies after her own ineptitude gets her killed, Goldmoon dies when Mishakal seems to desert her after she loses her faith, and so on. They got better after Raistlin defeats Cyan Bloodbane, the dragon who was causing the Nightmare.
 * There is a short story which deals with a young boy being brought to see a psychiatrist for some sleep-related problem. During a hypnotism session, the boy explains that there are some sort of aliens that commit Mind Rape on him while he sleeps and leave him a horrible wreck afraid to fall asleep. The psychiatrist gives him the drive to order them away and the next morning, he's able to sleep peacefully..
 * In Robert E Howard's Conan the Barbarian story "Black Colossus", Yasmela denies this trope, knowing that her lady in waiting will assume it's true; she really was awake when the apparition -- an Eldritch Abomination Stalker With a Crush -- menaced her.
 * In Shadows of the Apt, Ucteberi does this to the Bee-Queen.
 * In Jasper Fforde's Well of Lost Plots, Aornis unleashes her memories of Crimea on Thursday Next.

Live Action TV

 * Buffy the Vampire Slayer episode "Nightmares": All the worst nightmares of Sunnydale residents come to life, courtesy of . These range in severity from nightmares of embarrassment -- showing up in class in your underwear, forgetting how to read, etc. -- to Buffy getting buried alive and turned into a vampire and Xander being attacked by a knife-wielding Monster Clown.
 * Also, "Restless", where they are all almost killed in dream sequences by the First Slayer. Buffy defeats her by ignoring her.
 * And yet again in "Fear Itself", where the characters begin to manifest their worst fears and insecurities, e.g., Xander becomes invisible and inaudible, Willow's innocent magical lights go out of control and attack her, Oz begins turning into a werewolf in front of Willow, etc.
 * In the Stargate Atlantis episode "Doppelganger", an entity jumps from an alien crystal to Sheppard, then from him through various cast members, causing vivid nightmares starring a sociopathic Sheppard. The entity only scares people at first, until killing  in a
 * In the Star Trek the Original Series episode "The Menagerie," the illusion-casting Talosians attempts to bring the captured Capt. Pike to heel by momentarily creating the agonizing illusion that he is in Hell. Furthermore, they warn him that he if doesn't behave, then they'll dig deeper into his mind for the really nasty stuff!
 * In season 2 of Heroes, Molly Walker is tormented by what she calls "the nightmare man," but she refuses to talk to anyone about it. The nightmare man is later revealed to be.
 * In Superhuman Samurai Syber Squad episode "To Sleep, Perchance to Scream," a series of Dream Within a Dream situations is eventually revealed to be the Monster of the Week tormenting him via his alarm clock (talk about Everything Is Online!) once we get down to reality.
 * An episode of Charmed pits the Power Trio protagonists against their worst nightmares come to life after the Demon Of The Week gets his hands on some Sandman sand.
 * A first season episode featured a serial killer who developed a way to enter the dreams of women who rejected him. Killing them there meant they died in real life.
 * In Kamen Rider Double, the Nightmare Dopant torments people in their dreams, putting them into comas. In order to battle him, the protagonists transform into Double and then go to sleep, since the transformation places one person's consciousness in another's body. This creates an interesting fake-out moment, as a dream version of the character appears in addition to the real one, something the Dopant didn't anticipate.
 * In Lost Girl, a dark fae Mare who is a Dream Weaver infects people and fae with these in order to feed off their fear. Bo, the protagonist, has nightmares revolving around being abandoned and alone which is not a surprised given her background.

Tabletop Games

 * A known symptom of latent psychic abilities in Warhammer 40000. If it doesn't result in an unbelievably horrible death from the creatures of the Warp, it usually results in an unbelievably horrible death at the hands of the Inquisition.
 * In the Dungeons and Dragons universe, there is an epic monster known as a dream larva, a major threat usually sealed away in some other dimension. It is either a literal child of a god of dreams or a god's nightmare that has been so powerful that it absorbed a spark of his power and become sentient. In either case, its essentially Freddy Kruger on steroids, capable of messing up dreams of entire worlds at once. It also has a relity-warping power to assume the shape of everyone's worst nightmares simultaneously, so most mortals get heart attacks just seeing it.
 * Guess what? The only spell that can summon this abomination is an Epic spell, thus (almost) on par with spells that can, say, rains apocalypse from the heavens to an area as large as a city. Yeah, this creature is this trope, Exaggerated.
 * In 3.5's Monster Manual II we get the Nightmare Beast which, surprise, can induce horrific nightmares to any intelligent creature from a distance. Add Its immense size, the ability to trample smaller creatures and some pretty frightening spells and you have a monster made for inducing nightmares regardless of whether you are awake or asleep.

Video Games

 * In several routes of Tsukihime the protagonist has dreams of himself attacking and killing people, only to see the victims being reported in the news the next day. He actually ends up going temporarily insane from it, as he is convinced that he is the killer,.
 * The exception to this is
 * In the side-story/sequel, Kagetsu Tohya, the protagonist.
 * World of Warcraft has Potions of Nightmares, which "puts the imbiber into a slumber where they face and defeat their darkest fears." Doing so regenerates the character's HP and mana.
 * In the Vanessa Vancleef encounter, Vancleef poisons you with the Nightmare Elixir, causing you experience the worst nightmares of the instance's previous bosses.
 * In Pokémon, Darkrai can trap its victims in a neverending nightmare. Whether or not there is malicious intent depends on the game.
 * This is the main source of action in Catherine. The hero, Vincent, as well as a number of other men in his town are plagued by nightmares where they have to navigate up massive, constantly-disintegrating block towers while being chased by enormous monsters . And if you fail, you die in real life. Matters are further complicated by the fact that none of the men can remember their dreams when they wake up.

Web Comics

 * When Torg, Bun-Bun, and Kiki went on the Wayang Kulit vision arc in Sluggy Freelance, they each had to face their worst fears manifested. Torg saw himself bring death to all the women in his life and gradually become a demon. Bun-Bun relived his mother's murder, unable to intervene. And Kiki was given a PB&J sandwich that she couldn't cut the crust off of.
 * Subverted by Bun-Bun not running away or cowering in fear, but instead getting pissed off like usual and beating the crap out of the Shadow trying to scare him.
 * Fall in Parallel Dementia has dreams where multiple supernatural entities (called "Nightmares") try to influence her and each other. Once she was convinced to sleepwalk to the edge of a second story balcony and climb on the railing before she was woken up.

Web Original

 * Whateley Universe example: Bladedancer, the Handmaid of the Tao, was attacked through her dreams by mages of The Black Tong (who are on another continent and are performing dark necromantic rituals to power this attack). Too bad for them that Whateley Academy has its own patrol for the astral realms.

Western Animation
"Doctor Destiny: Coming here was the mistake of your life. See, the closer I am to someone, the stronger I get. I'll be able to enter your brain, even if you're wide awake.
 * American Dragon Jake Long had this as an episode, the nightmare was only realesed becuase Jake tried to cheat on a test.
 * In The Powerpuff Girls episode "Power-noia", Him visited the girls in their sleep and tormented them with the aforementioned worst nightmares.
 * This is inversely done to the Sand Man via the girls when he gets fed up with constantly having to put people to sleep and get no sleep for himself, thus leaving him to decide to just force everyone to sleep at once. The girls find out that they have the power to communicate through dreams and use this to give the Sand Man so many nightmares that he never wants to sleep again. Yeah...
 * In the Justice League episode "Only A Dream", the Justice League faces John Dee, AKA Doctor Destiny, a criminal accidentally given Psychic Powers by an experiment, who uses his new abilities to torture and kill his ex-wife in her dreams, then goes on to torment our heroes. He bites off a bit more than he can chew, though, when he taunts Batman, who's powering through with willpower and coffee.

Batman: My brain's not a nice place to be."


 * If it weren't for the fact that it's Batman, that would be a Noodle Incident; as it is, it's kind of like a pre-fired Chekhov's Gun.
 * Doctor Destiny also existed in the comics, with much the same MO--however, here, it's notable that he gained his powers from a device which was retconned to be powered by a special ruby... that originally belonged to Dream of Neil Gaiman's The Sandman, before it was officially split off from the main DCU.
 * One of the experiments in Lilo and Stitch The Series could turn into the thing a person feared the most. It even got to Nani by disguising itself as Scary Black Man social worker Cobra Bubbles and threatening to take Lilo away from her.
 * A later episode has a experiment that can invade dreams and turn them into nothing but nightmares. It nearly does this to Lilo had Stitch, Pleakly and Jumbaa not intervened.
 * The Duck Tales episode "Nothing to Fear" saw Magica DeSpell threatening Scrooge and company with a magic raincloud that caused a person's worst fears to manifest. At first, the trope was Played for Laughs; thus, goofy neighbor kid Doofus was threatened by a school bully, the nephews had to deal with a video game villain and their overbearing math teacher, while Scrooge was threatened by bill collectors who wanted to take away everything he had, including Huey, Dewey, and Louie. Then, the story became Darker and Edgier, as the characters experienced more serious fears of rejection and abandonment.
 * A whole Spongebob SquarePants episode was devoted to this. SpongeBob travels into other main characters' dreams and messing them up, making them nightmares. Even Patrick is annoyed by his best friend's presence in his dreams.
 * Well, he doesn't necessarily cause nightmares, but he certainly gets on everyone's nerves. Plankton and Sandy's certainly count as nightmares, while Squidward's is an arguable case. The rest are just really annoyed.
 * And he wasn't really trying to cause problems. But he is SpongeBob...
 * Patrick wasn't really annoyed either, he was just sitting there on the ride doing nothing.
 * In The Tick, Mr. Mental controls Tick by submitting him to his worst nightmare: having a dayjob in an office.
 * An episode of Hercules: The Animated Series had Phantasos using a shroud similar to his brother Morpheus to give people bad dreams.
 * In the G.I. Joe episode "Nightmare Assault", Dr. Mindbender tortures the Joes with these. His scheme is foiled by Low-Light, who has had nightmares about his abusive father all his life and is pretty used to it by now.
 * In The Real Adventures of Jonny Quest episode "Thoughtscape," Jeremiah Surd tries to stop Jonny and Benton from saving Jessie by trapping them in their own worst fears: Jonny's is being a disappointment to his father, and Benton's is his family dying because of him.
 * Extreme Ghostbusters had "Fear Itself", an episode devoted to a ghost that did this. Turned out
 * From The Legend of Korra, Big Bad Amon is this to Korra.