Gusteau: [chuckles] But you don't, Remy. You never did. [disappears]
Detective Bob is a detective. He's in the middle of an important case when, suddenly, a whole bunch of traumatic stuff happens to him, he hits his head on an orange crate, and he somehow ends up taking a lot of drugs. Now, wherever he goes, he is followed by a talking, pink hippopotamus named Oswald, that only he can see. Bob is hallucinating!
This is bad for the case, right? Clearly, Bob is no longer mentally fit to do his job, and should go somewhere to receive treatment until Oswald goes away. Right? RIGHT?
For you see, Oswald is a manifestation of Bob's subconscious. He thus knows all about the case, including details that Bob apparently ignored or didn't quite put together. So instead of impairing Bob's ability to function, Oswald is basically akin to temporary mental superpowers, helping to point Bob in the right direction.
In real life, hallucinations usually aren't so helpful, and you probably shouldn't take advice from one.
SPOILERS to follow, as some of these hallucinations aren't identified as such until The Reveal.
- "Radar Man" from Paranoia Agent appears to have this happening to him. Or...the sexy figurines might actually be talking to him. It's that kind of show.
- In the Sin City story The Big Fat Kill, while driving Jackie Boy's corpse to the tar pits for disposal, Dwight starts hallucinating that Jackie Boy's talking to him, taunting him about how screwed he is about the whole situation. Dwight answers "Sure, he's an asshole. Sure he's dead. Sure, I'm just imagining that he's talking. That doesn't stop the bastard from being absolutely right."
- Played with in Ratatouille, where Remy hallucinates Gusteau advising him about cooking, and life in general. Until Remy finds out Gusteau has a son:
Gusteau: I have a son?!
Remy: How can you not know you have a son?
Gusteau: I am only a figment of your imagination! You didn't know, how could I?
- In Gravity when Stone has quietly accepted that she is stuck in a shuttle without fuel and is probably going to die, Kowalski, who she believed to be dead, suddenly appears outside the shuttle, lets himself in, and tells her that all hope is not lost, as there is a trick to get the shuttle moving, urging her to not give up. Kowalski then disappears into thin air when Stone looks the other way for a second, revealing him to be a hallucination, but she realizes that his method to get the shuttle moving actually works.
- In Mad Max: Fury Road Max has a recurring hallucination of a young girl. At one point she appears in front of him and reaches towards him which causes him to instinctively cover his face, and this winds up saving his life by giving Max an Impaled Palm instead of an impaled head. She also appears at a critical point in the movie and gives Max the idea to take the unguarded Citadel.
- Adrift (2018): Tami's vision of Richard helps her keep her focus and drive long enough to reach help.
- Diario de un Zombi has Erik, a masked opera dancer who leads the protagonist to the last living humans in Barcelona.
- Red Mars Trilogy has Hiroko lead Sax Russel, lost and freezing to death, back to his rover. It's left open if she was a hallucination or real.
- In The Story of the Stone, Master Li and Number Ten Ox drink hallucinogenic tea in order to take a "mind trip" to the Chinese Hell; it is deliberately ambiguous whether their experience is this trope or a genuine spirit journey.
- In the Inspector Rutledge series, Hamish—the soldier Rutledge has constantly hallucinated since he executed him during WWI—sometimes points out things that Rutledge's conscious mind has missed. That being said, Hamish is just as likely to be hostile and outright disruptive.
- In You, main character Russell frequently sees the heroes of the game he's working on, who offer encouragement and cryptic advice. Exactly why this is happening is never stated, since he isn't brain damaged or mentally ill; after many of the encounters, however, he mentions waking up, so this may overlap with Dreaming the Truth.
- One interpretation of a chapter of World War Z in which a downed pilot comes into radio contact with an extremely helpful Voice On The Radio, who does things like reiterate her survival training, help her navigate through semi-familiar terrain, motivate her, and even alert her to danger that she had not yet heard. After her rescue, no trace of the helpful woman on the radio could be found.
- One of the supporting characters of Geoph Essex's Jackrabbit Messiah is the omnipresent voice in Jack's head, which is paradoxically (though apparently not uncommonly) the only thing that keeps the rest of Jack's symptoms from overwhelming (and paralyzing) him, making him a pretty useless hero without it.
Amity Sheridan: It keeps the rest of his hallucinations and delusions in check.Lieutenant Springer: The biggest monster in the closet intimidates the rest.
- In the Polish writer Anna Chmielewska's whodunit, Wszyscy jestesmy podejrzani, the main character has hallucinations of a snarky, sassy Big Red Devil who gives her hints and nudges towards solving the case.
- In The Postman, Gordon is encouraged during his effort to escape (by pulling himself up and over the beam he's tied to) by visions of the dead, including the computer Cyclops, Ben Franklin (and his stove), and the original owner of his postal carrier's uniform.
- In the Dresden Files, Harry occasionally gets visited by his subconscious while he's asleep. It usually chews him out about something then gives him a bit of insight or information Harry himself didn't figure out and moves the plot forward.
- The protagonist of Johnny Got His Gun lost all four limbs, his sight and hearing and is therefore shut in, living his days out like a vegetable in his hospital bed. In one of his fantasy sequences, Joe's father reminds him to use the morse code he learned in his youth to communicate with the outside world.
- Happened a few times on Bones:
- Bones hears the murder victim telling her information about herself and the case.
- In the Hockey episode, Booth gets advice on the investigation from a famous NHL player after being knocked unconscious.
- When Booth was trapped by the Gravedigger on a ship that was to be sunk, he received help from the ghost of a private who died in Bosnia(?) while under Booth's command. Booth knew it was a hallucination, but there were things that he did that needed two people to do.
- Or, if you prefer Doing In the Wizard, he could have been hallucinating the obstacles as well as the ghost who helped bypass them. This still doesn't account for Bones seeing the guy in the graveyard at the end of the episode (though she doesn't know the significance of the soldier being there)
- When Booth was about to have A Date with Rosie Palms to donate sperm for Brennan to artificially inseminate with, Stewie from Family Guy appeared on the TV and gave him relationship advice. This one prompts some medical investigation and he ends up discovering (in time) a serious brain tumor which may or may not explain some or all of the previous hallucinations he experienced that season.
- In Sherlock episode "His Last Vow", when Sherlock is shot by an assassin, he instantly enters into a not-so Dying Dream, in which first his brother Mycroft appears to help him determine which way to fall down and later Moriarty, of all people, giving him the motivation to come back to life.
- In CSI: Miami Eric gets shot in the head. When he recovers, he hallucinates Speed, who died several seasons ago. The hallucination points him to evidence he missed, and helps him crack the case.
- In the Eureka episode "The Ex-Files", Carter's hallucination of Stark seems to have a bunch of knowledge that you wouldn't expect him to. Most of that knowledge (like Stark's shoe size) is totally useless, though he does point Carter in the direction of one particular clue that's important to the episode plot.
- Misao from ''Doubutsu Sentai Zyuohger hallucinates the three zyumans that were killed in the process of creating his powers. How helpful they are varies, but they usually do push him in the right direction. Initially, they pose themselves as ghosts that came back to haunt him, but admit being hallucinations created from his guilt not so long after.
- Fringe: while trapped on the other side and brainwashed, Olivia hallucinates a version of Peter who tries to convince her that she's in the wrong universe.
- In Glue, James, while on an acid trip, hallucinates his dead boyfriend Cal, who reveals the location in which he’d hidden the contract for the horse their families co-owned.
- In the last couple of episodes of the fifth season of House, House gets advice on a case from a hallucination of Amber, who had died in the season four finale. Unfortunately, as he continues hallucinating, it's not limited to Amber and the hallucinations become... less helpful...
- In a grim variant, Gibbs' former marine commander on NCIS wound up a fugitive when he was suspected of stealing a cache of Saddam Hussein's money recovered in Iraq. He was goaded on in his quest to find and eliminate the real thieves by a fellow marine, who turned out to be an hallucination of a man who'd died in combat years earlier.
- In the episode immediately after Kate was shot, most of the cast either imagined or outright hallucinated a parting conversation with her ghost.
- Same happened with Mike Franks.
- In the episode immediately after Kate was shot, most of the cast either imagined or outright hallucinated a parting conversation with her ghost.
- The entire plot of Series/Perception involves Daniel Pierce, a schizophrenic consultant for the FBI, whose hallucinations often help him connect the dots of a case his conscious mind hadn't noticed.
- On NYPD Blue Sipowitz had a hallucination conversation with his dead partner Bobby Simone, who convinced Andy to take his new young hotheaded partner John Clark Jr. under his wing rather than let him go his own way, which was leading down the wrong path.
- The (unfortunately) short-lived TV series Raines wore this as it's hat. The main character, a police detective played by Jeff Goldblum, had hallucinations of the victims of the crime he was investigating, who followed him around until he solved the case. The hallucinations would actually change slightly in appearance and manner as he learned more about the victim. He was completely aware of them not being real—in fact, the hallucinations would sometimes comment on it.
Raines: What do you want?
Sandy Boudreau: It's your imagination, Detective; I'm just a figment.
Raines: What do you want?
Sandy Boudreau: I want you to find out who killed me.
Raines: Then you'll go, back to whatever dark, twisted, malfunctioning part of my brain that you come from?
Sandy Boudreau: Yeah.
- One episode of Sir Arthur Conan Doyle's The Lost World sees Marguerite stepping into a booby trap and falling into a pit with spikes. She gets hurt and suffers a concussion. While Challenger gets help she hallucinates about her best friend Adrienne who keeps her awake so Marguerite doesn't fall asleep. Later it turns out to be a Not-So-Imaginary Friend — which freaks Marguerite out.
- Stargate Atlantis: When McKay gets trapped at the bottom of the ocean in a broken puddle jumper, he has a hallucination of Carter that's his subconscious trying to keep him from doing something that will get him killed. He tries to get her to strip down, only for the hallucination to tell him that the real Carter would never do that, so she won't either. McKay is, understandably, annoyed.
- In "I Think I'm Gonna Like It Here" (S09, Ep01), Sam creates versions of Dean and Bobby who help him decide whether he should continue to fight or accept death.
- Subverted in "Repo Man". Sam accepts the help of Hallucifer to solve the mystery of the week, instead of ignoring or banishing him as usual. At the end of the episode, Sam tries to banish Lucifer again but it doesn't work. Turns out willingly accepting Lucifer's help has increased his control of Sam's mind.
- May occur in Twin Peaks, particularly The Giant who appears at critical moments to give Cooper hints on the case. This being Twin Peaks, however, it's unclear whether it's this trope in action or something else.
- In the first season of Veronica Mars, Veronica and Duncan gets vague messages from a hallucination of [[Spirit Advisor Lilly, who was murdered in the show's Back Story, providing hints towards solving the mystery of Lilly's murder.
- In the The West Wing episode "Two Cathedrals" (which is widely considered one of the greatest single episodes of television of any genre in the history of the medium), President Bartlett has a soul-searching conversation with his personal secretary, Mrs. Landingham, for whom he attended a funeral earlier that same day.
- The Kid Detective show based on the Half Moon Investigations used this for a Eureka Moment (less of a form of brain damage or insanity and more of a kid's over imaginative imagination) where Fletcher argues with his own imagined version of the school's Alpha Bitch to understand both how and why she didn't commit the crime of dumping dye chemicals into the school's pool and delaying a swimming competition. Naturally, she didn't do it - it was one of the school's swimming pool team who did.
- In an episode of iZombie, Liv eats the brain of a man, who was known to hallucinate. While investigating his apartment, a TV weatherman she has met once shows up and claims to have bought marijuana from the deceased man. They investigate the case together, with the weatherman occasionally mentioning the temperature in both Fahrenheit and Celsius scales, much to Liv's annoyance. It's not until the end that she realizes that the Celsius number doesn't match the Fahrenheit number after a simple conversion. Just then, she turns on the TV and sees a live broadcast with the weatherman on it. Her companion then vanishes. She realizes she's been hallucinating him thanks to the brain she's eaten. However, the "temperature" numbers the guy kept repeating are actually a hint to unlock the dead guy's safe. So the hallucination actually was helpful, it was just using the memories of the dead guy instead of her own.
- Cloud's visions in Final Fantasy VII - variously shown as a voice in his head, a spectral version of himself or a child version of himself - spends a lot of time giving him hints. It reminds him of who Reno is even though he's forgotten, admonishes him if he decides to get sidetracked from his goals to go and mess about with prostitutes, and drops heavy hints about Tifa's evasiveness and where the cracks in his story lie. In one scene, when Cloud is possessed and trying to give Sephiroth the Black Materia, the player briefly controls one of the hallucinations running around trying to stop Cloud, but it doesn't work.
- Bioshock Infinite: During the Burial at Sea DLC, Elizabeth speaks to Booker, who should be dead at this point in the story. At first, it's implied he could be a ghost, considering the precedent for one previously. However, eventually Booker himself reveals that he's just a hallucination Elizabeth uses as mental support.
- In Broken Sword: The Serpent's Curse, Marques appears in George's dream and tells him that Langham must be stopped from using Lucifer to destroy Jehovah, that George has to protect the balance and that he has the answer in his hands. When George wakes up, he holds the medallion in his hand.
- During Hatoful Boyfriend, Ryouta is advised by a stranger and then is given pause when another character thinks he's snapped and started babbling to the air. He asks the stranger if he's a hallucination and is told "... If I was, that would mean you're asking a hallucination whether or not he's a hallucination. Does it matter? Maybe I am, or maybe I'm not." The advice is good, but that doesn't convince Ryouta one way or another. The stranger is actually a ghost and Invisible to Normals.
- Higure Anghel exudes hallucinogenic pheromones which he is not immune to, but while his hallucinations are often strange and don't seem to have much to do with the situation, they give him insights that more sober characters lack and are excellent for Epiphany Therapy. And at some level they may be real anyway.
- In The Order of the Stick, Lord Shojo explains he could be this.
- The Goddess of Clothing in Sandra on the Rocks is Lavali's hallucination created from frustration and dehydration during her time with Sandra, Tatiana and Domenico on a tropical island. So far, she's been quite helpful, for example giving advice to solve Sandra's modesty issue. She's also aware that she's a hallucination.
Goddess of Clothing: Yeah... Look, I'm going to level with you. I'm not so much a "goddess" as a "stress-and-dehydration-induced hallucination".
- In Twig, Sylvester makes use of hallucinatory versions of his friends to help him plan his actions and consider new approaches, with the hallucinations occasionally acting to offer suggestions of conscience and ruthlessness depending on how Sy remembers them. He also uses them to model his friends, for example his hallucination of Mary helps him shoot her through the knee by warning him she'll try to disarm him.
- The Simpsons:
Spirit guide: I'm only a memory, Homer. I can't provide additional information.
- Lampshaded on when Homer tried to access information from his coyote spirit guide while conscious:
- The Twin Peaks example is spoofed on "Who Shot Mr. Burns, Part 2". Chief Wiggum has trouble making sense of the backwards-talk until Lisa just snaps and tells him straight-up.
- In "The Spy Who Learned Me" a head trauma causes Homer to see the fictional James Bond-esque character Stradivarius Cain who coaches Homer on how to be a better husband towards Marge.
- Skipper of The Penguins of Madagascar has his mind erased by Dr. Blowhole and suffers through two spirit guides trying to help him before his mind settles on Alex the Lion.
- After Henchman 24 dies on The Venture Bros., his ghost haunts Henchman 21, and starts warning him of danger and giving him advice in combat. Eventually, he explains that he's just a figment of 21's imagination, and all his help just gave 21 the confidence to do what he already had the capacity to do, including letting go of his dead friend.
- Samurai Jack: In "Episode XCV", Jack experiences a hallucination of his younger self who berates him for his actions and choices. At one point, the hallucination looks behind him and warns him that his tied up enemy Ashi is gone from where he left her.
- In the Quack Pack episode "Ready, Aim... Duck!", a fictional video game character named Captain Jack keeps appearing in front of Donald and urges him to confess to his Snowball Lie.
- We Bare Bears: In "Baby Bears Can't Jump", the Bears are losing a basketball game against a gang of street urchins, and take a time out to discuss their strategy. When the "discussion" turns into a furious argument, the Bears suddenly imagine that the image of Charles Barkley from a lenticular trading card comes to life and gives them a pep-talk about the importance of teamwork.
- In his book Hallucinations, Oliver Sacks reports that many people who experience Hearing Voices claim that they are these, with only some of them experiencing the stereotypical malevolent kind.