This character is a hero, fighting the good fight and defending the innocent from the forces of evil. Not everyone understands the nature of their struggle — in fact, many decry them as being insane — but if only they knew what the hero knew then they would understand that their goals are noble and their methods perfectly justifiable (if a little extreme). There's only one problem:
The struggle is imaginary.
The Trope Namer is Don Quixote, a crazy old man who wanted to be a heroic knight but had zero knowledge of what knights actually were, thanks to being born several centuries too late. He saw some windmills and believed that they were actually evil giants, and set off to attack them, in the most famous scene of the novel.
A Windmill Crusader is not a Straw Hypocrite: While he might be a Heteronormative Crusader or Principles Zealot, he is not a dishonest person who will try to trick people into a struggle against windmills for the greater good. No, he honestly and wholeheartedly believes the windmills are giants and is desperately trying to save everyone from this non-existent threat.
So, why did he mistake windmills for giants in the first place? Well... maybe he's crazy, maybe someone gave him misinformation that he didn't check up enough, maybe he's interpreting something incorrectly, or maybe he blindly believes some religious or ideological dogma.
Fighting a threat that others mistake for a windmill but actually is a real threat doesn't make the character a Windmill Crusader at all. However, it makes it easy to get mistaken for one. Also, a character can fight a real threat and still be a Windmill Crusader: either by misunderstanding what the threat really is or by fighting real threats as well as windmills.
- Martian Successor Nadesico: A major theme, especially the latter half of the series. Amusingly, one could say that Gai Daigouji basically is Don Quixote, only this time some of the windmills really are giants. Naturally, he doesn't last very long.
- Ranma ½: Tatewaki Kunō carries elements in this, mainly when he attacks Ranma, believing that he has enslaved Akane and the "Pig-Tailed Girl". The first problem with this is that Ranma and the Pig-Tailed Girl are in fact the same person.
- WORKING!!: Inami was taught from a young age by her father that males would all try to rape her (the "windmill"). By the time the story rolls around, she has a severe fear of men because of this, including said father. When she falls in love, she's trying to get rid of the training, but it's been so deeply ingrained in her psyche that, even being able to see the "windmill" for what it really is, isn't enough to stop the crusade.
- The principal from Angel Densetsu has the main character, Kitano, threatened as though he is the demon king himself, going as far as to bring people into the school, with the sole purpose of beating up Kitano, or better yet, get him expelled. Of course, Kitano is anything but evil — he merely looks evil.
- In Is It Wrong to Try to Pick Up Girls in a Dungeon?, Argonaut's Establishing Character Moment is him attacking a windmill after mistaking it for a giant, only to get swatted aside by the blades and mocked by the townsfolk in a reference to Don Quixote. He then goes on to record his feat in his "Hero Diary". The revelation of his Obfuscating Stupidity later on in the story makes this seem less like an act of delusions and more like an intentional attempt at getting people to laugh.
- Bitchy Butch: Butchy is infamous for this among her fellow gay rights activists. She's paranoid about men (oppressors all of them!) and heterosexual women (traitors!) as well as lipstick lesbians (potential traitors, "not real", or whatever), and see the religious right in every shadow.
- In Lucifer, we have the political faction "Efferul for Lucifer" that fights on the Morningstar's behalf. He is not amused, as their agenda is based on a very misguided vision of what he wants and needs.
- Quantum and Woody: Played straight for drama. Quantum is convinced that David Warrant engineered the deaths of his and Woody's fathers, and tried to kill them in the accident that gave them their powers. He still suspects this even after repeated non-violent encounters with Warrant, including one time when Warrant helped save Woody's life. It reaches cataclysmic proportions when Quantum absorbs all of their shared power, neutralizing Warrant at a critical point as he tries to save the Eternals on the Moon.
- Dilbert features many surreal jokes based on the premise that one character lives in his or her own little reality. Sadly, this is often a character who has power — or who gains power by enforcing his or her crazy perceptions on others.
- A lighthearted example occurs in Peanuts. Linus' annual quest to wait for the Great Pumpkin and prove he exists is an example of pursuing a windmill. (Well, probably. All that is known is if the Great Pumpkin does exist, Linus has never succeeded in his goal.)
- In The Dresden Fillies: False Masks, the Order Triune truly believe that Harry Dresden/Blackstone is Obsidian, an evil overlord from the distant past who had Resurrective Immortality. The Order was formed to combat Obsidian in all his incarnations and has killed all magically powerful stallions who look like him, believing them to be Obsidian reborn. A quick list of what they're wrong on: Harry is Obsidian? Wrong! Obsidian is Novel Notion? Wrong! Obsidian was any of those stallions they killed? Wrong! Obsidian ever came Back from the Dead at all? WRONG! Turns out they got that last one correct after all. Problem is, it still wasn't Harry, and he wasn't even IN Equestria.
- They Might Be Giants is named after Quixote's idea about the windmills, as the protagonist (who believes himself to be Sherlock Holmes) hunts down a possibly-imaginary Professor Moriarty.
- In Downfall, Hitler and some of his closest followers are portrayed as tragic anti-villains who desperately tried to save the world from a world-engulfing conspiracy that they honestly believed to be real. As Berlin falls they face what they believe to be the twilight of mankind itself. Hitler himself is portrayed as a person who is most likely insane, while his followers are rational except for their misguided belief that he is a legitimate leader rather than a madman. Their actions make total sense when one takes this tragic belief into account.
- In A Beautiful Mind, the protagonist is the Real Life Nobel Prize winner John Nash, hired by the US government in their struggle against terrorism. What neither Nash nor his closest superiors know is that Nash is not only brilliant but also a paranoid schizophrenic who takes orders from two kinds of US officials: The real and the imaginary. The later "branch of the government" takes him on a quest that only keeps getting weirder as the (imaginary) terrorists get closer to their nefarious goal of planting nukes in American cities.
- The Last Temptation of Christ:
- Jesus is initially portrayed as the insane kind of Windmill Crusader. This is played straight for most of the movie, he even gets cured of his messiah complex and gets to live a normal life. Later events radically change the picture.
- Paul is briefly portrayed as the misguided kind of Windmill Crusader. However, he is quickly deconstructed as a Straw Hypocrite who simply doesn't care if the gospel he preaches is true or not.
- Where Eagles Dare: Played with/inverted; all of the team are sent into the castle to rescue the general, but only Smith and Mary are aware that the whole setup is a complete fabrication, and most of the rest of the team are the bad guys.
- Arguably, the Operative from Serenity. He'll do anything to create an Alliance without sin, mistaking himself for being a Soulsaving Crusader... until Mal and crew give him a front-row seat to what such a thing looks like.
- God Bless America: Frank, who seems to believe that he's actually doing something worthwhile. Unlike Roxy, he seems rather naïve — not unlike the mentally-handicapped television kid he keeps identifying with and pitying for all the wrong reasons.
- The main character in Creation of the Humanoids is a high-ranking member of a radical anti-robot organization. Recently, they've finally found evidence that the robots actually are engaging in a conspiracy of some sort — have the robots finally Turned Against Their Masters, just like the main character's organization has been warning against? Well, no. The robots really are up to something, but it's nothing that anyone has to be afraid of.
- In Dr. Strangelove, the Trope Namer for General Ripper launches an all-out nuclear attack on Russia because he's convinced himself that they're using water fluoridation to "sap and impurify our precious bodily fluids".
- The Man Who Killed Don Quixote:
- Javier/Quixote has hallucinations and attacks windmills believing them to be giants, just like the Trope Maker himself. He also sees Toby as Sancho Panza and sees Muslim pilgrims when he's actually looking at a flock of sheep.
- Toby attacks windmills thinking they are giants as well, at the end. Earlier on, Toby believes he found gold coins but late realizes that they're actually steel washers.
- Don Quixote: The Trope Namer is Don Quixote, a delusional would-be knight errant who engages in a constant struggle against evil sorcerers and wicked monsters that exist only in his own mind. Most famously in chapter thirteen, he mistakes a group of windmills for "thirty or forty outrageous giants" despite his squire Sancho telling him that he is wrong, and gets thrown into the air by one of the sails when he sticks his lance into it.
- In the YA novel The King of Dragons, the protagonist's father is this. His severe PTSD from military service causes him to believe that terrible things will happen if he and his son are found by the authorities, so he gives him Survival Training from Hell. At the end of the book, he is recovering, and tells his son, "I mistook molehills for mountains, but I taught you how to climb mountains."
- In the Ace Diamond novels, a cab driver suffers a nervous breakdown when his wife destroys his pulp collection and he starts to think he his pulp PI named Ace Diamond and that all fictional Private Investigators are real and friends of his.
- In Going Bovine, there is a constant doubt on whether Cameron is really traveling across the country and saving the world or simply hallucinating due to his mad cow disease.
- Hermione wanders into this territory in Harry Potter and the Goblet of Fire when she forms a club (consisting of, well, herself) to fight the oppression of house-elves in the wizarding world. While she has only the best of intentions, and she is absolutely correct that some of the house-elves are treated abominably by their masters (such as Dobby during his time with the Malfoy family), she takes on the problem in a very badly arranged fashion. She starts with the house-elves of Hogwarts, who are extremely happy and very well treated — Dumbledore is even willing to give them days off and a salary if they want it, which most of them don't. She also fails to realize that the house-elves as a species prefer living as indentured servants of sorts, and her efforts to persuade them otherwise seriously upset them.
- The Dresden Files: Donald Morgan, Harry's "parole officer", who honestly believes Harry is tainted and going to jump off the slippery slope if he's given an inch. The initial books (all told from Harry's point of view) initially presents Morgan is simply a power-abusing jerkass, but Harry's view of Morgan actually softens slightly when he (much later) realizes Morgan sincerely believes he's dangerous. The real irony comes in "Turn Coat," when Morgan shows up at Harry's door, claiming he's been framed for murder and his own coworkers are after him. As Morgan is dying he tells Harry that the reason he came to him was because he knew Harry understood what it was like to be an innocent man hunted by the Wardens.
- Sherlock Holmes, in The Seven-Per-Cent Solution. His obsession with the master criminal Professor Moriarty (both in the book and in the Conan Doyle stories) is explained as simply a byproduct of his cocaine addiction. In truth, Professor Moriarty was his mathematics tutor.
- Emily Greenstreet of The Magicians, having managed to accidentally disfigure herself with magic and get her ex-boyfriend killed in his efforts to heal her, is now of the opinion that all magic is evil, that it's practitioners are nuclear bombs waiting to go off, and that the government should raid Brakebills before they blow up the world. Putting aside the fact that Emily is in denial over the fact that the magic-related accident was entirely her fault, she's completely wrong: qualified magicians are inveterate hedonists who can barely be arsed to do anything, least of all blow up the world; Brakebills actually cracks down on potentially dangerous behavior in advance - as evidenced by the fact that Emily was expelled; and finally, magic is neutral and the only danger it poses to the world crops up when the Jerkass Gods decide they don't like people having their level of control over reality. For good measure, the aforementioned hedonism means that Emily can't be bothered to actually pursue her agenda.
- Buffy the Vampire Slayer: While Buffy has The Cuckoolander Was Right as an inherent trait, the episode "Normal Again" subverts this when Buffy is drugged and hallucinates that she's been insane all along and that Sunnydale is only in her mind. In this hallucination, Buffy is an insane Windmill Crusader before the series started, and has been locked in a mental institution throughout the whole series.
- In Game of Thrones, the Night's Watch has developed this reputation among Westerosis during the present era since many believe the mystical creatures they're fighting (White Walkers, Wights, etc.) to either just be myths or things of the past.
- An episode of Smallville has a similar premise, with Clark being given a hallucination in which he is a mental patient who only thinks he is a super-powered alien. Specifically, in an inversion of an incident in the pilot, he learns that Lex lost both his legs in a car accident after Clark jumped out in front of him insisting he was saving him.
- In Inside Scoop they try to pin society's problems on left-handed people, and propose that we should "ban left marriage". (It's a parody of homophobes, of course.)
- Grotesco 2: In this Swedish comedy show, some religious leaders take their homophobia a few steps beyond Heteronormative Crusader straight into windmill territory. A Protestant, a Catholic, a Muslim and a Jew all agree that it's not their fault they have been murdering each other for millennia — nope, the gays made them do it! Oh, and it's not Satan's fault either: He's also an innocent victim of the horrible gay conspiracy.
- Degrassi: The Next Generation gives us Emma Nelson. It's not enough to boycott genetically modified foods or even petition to have them removed. She's convinced the lunch lady's trying to poison them.
- America Unearthed has host Scott Wolter as a fringe history Don Quixote.
- A major source of humor and conflict in Parks and Recreation is Leslie's tendency to latch onto nearly every local problem or social justice cause she thinks of, even when it's a blatant non-issue that nobody except her cares about (for example, calling for a government bailout over Videodrome going bankrupt despite the fact that nobody cares in the slightest or raising a stink over there being no female garbage truck workers even though no women in town are really trying to get into the job anyway). Sometimes it turns out she had something of a point but more often than not it's clear that she's just too zealous for her own good. Ron considers it to simultaneously be both her greatest attribute and her most obnoxious quality.
- Doctor Who features a particularly weird 12th Doctor episode called "Listen", which revolves around the Doctor and Clara trying to find an alien species that is completely undetectable except during two instances; a dream the doctor once had about a hand grabbing him from under the bed and at the end of the universe. Turns out, the Doctor is a Windmill Crusader in his spare time and his pursuit of these imaginary creatures came from his inability to admit that he is scared of the dark. And the hand grabbing him turned out to be Clara.
- The Netflix true-crime series Tiger King is centered around a feud between an Oklahoma "zoo" owner "Joe Exotic" and woman named Carole Baskin who runs a big cat sanctuary in Florida. Carole had been trying to get roadside zoos like his shut down, to no avail, and ends up beating him at a copyright infringement lawsuit with a million dollar settlement. Her plan was to take the zoo as collateral and give the animals to more humane zoos. From that point on, everything bad that happens to Joe is because of "that bitch Carole Baskin". All of his friends try to tell him that he needs to just leave her alone because she has the financial means to keep fighting it in court while he doesn't. He will not listen. He blames her for a fire, his husband's death, and so on. He ends up trying to hire a low dollar hitman (who was actually an undercover FBI agent) to kill her. He's now serving 22 years in prison for murder for hire and violations of two animal welfare laws.
- The Computer became paranoid about the Commies (who had disappeared long before Alpha Complex was built) when an early malfunction caused it to mistake 1957 civil defense files as being up to date. Some disgruntled citizens soon re-formed the Commies (as best they could figure them out) because The Computer was paranoid about them, after which their role varied from No Mere Windmill to Strawman Political to The Scapegoat (for PURGE, or some other secret society, or just self-serving individuals).
- The "Wobblies" society also fall under this. At first, every Troubleshooter sent to investigate this potentially dangerous group reported that they couldn't find anything at all (since the Wobblies didn't exist) and were summarily executed for laziness, incompetence and/or collaborating with the Wobblies. Eventually, the Troubleshooters had to found the society themselves just to have something to report on.
- Dragon Age:
- Dragon Age: Origins: Loghain believes that the Darkspawn are not a threat, but the neighboring country of Orlais (who occupied Ferelden for much of his life, until he and King Maric drove them out for good) are still the primary concern for the defense of the country. Interestingly, he considers the Grey Wardens themselves to be dangerous Windmill Crusaders who might weaken the nation's defense against Orlesian invasion, even though the Darkspawn threat is quite real.
- In Dragon Age II it's revealed that some nobles of Orlais do want to reconquer Ferelden for... some reason (national pride, boredom, take your pick...) and are in disagreement with their Empress (who actually planned to marry the King of Ferelden before his death in Origins. So Loghain was on the ball about that, but being Properly Paranoid doesn't mean you're right about everything.
- Word of God and notes found in the "Return To Ostagar" DLC confirm that yes, Cailan was planning on leaving his wife — Loghain's daughter — for the Empress of Orlais and yes, Loghain found out about it, which factored into his decision to betray Cailan. Loghain's biggest error of judgement is that, as Flemeth puts it, believing that "the Darkspawn are merely another army that can be outmaneuvered."
- Maximillion of Northshire, a quest giver in World of Warcraft's Un'goro Crater, will take the player's character on a long quest to defeat the "evil dragons" in the area, rescue the "purse" of a "fair maiden" — a male Blood Elf — who dropped a box of unknown contents from the hot spring, a second fair maiden from a high place by throwing her off a cliff, and rescued a third maiden from a "foul beast" by killing her parrot companion. Finally, he takes you to something that is actually dangerous: kill an Azeroth-equivalent Tyrannosaurus rex... by running away from it while throwing his armor at it. In the end, he's convinced he's truly done good. Also notable is that one of the rewards for his final quest is a trinket called a Toy Windmill. The entire quest chain is a huge reference to/parody of the Trope Namer, Don Quixote.
- N from Pokémon Black and White truly believes he's rescuing Pokemon from people, but only because Ghetsis only allowed him to interact with abused Pokemon. He planted the idea into N's head that he was the "hero", then used him to further his own plans of regional domination.
- The four old men of Amur in Final Fantasy III. They believe they're the real Light Warriors.
- Spec Ops: The Line: Captain Martin Walker goes into the game trying to rescue the survivors of a sandstorm-ravaged Dubai while dealing with the rogue Damned 33rd and their leader Joesph Konrad. Except that Konrad killed himself prior to the events of the story, and that taunting voice Walker hears for most of the game is all in his head. All those people shooting at him and his squadmates are just trying to keep that crazy gung-ho American from destroying what little hope the survivors have left.
- Agent Riggs claims that the events in Dubai since the sandstorm fell and the martial law imposed by the Damned 33rd would lead to a U.S.-Pan-Arabian war if news of it leaked, and seeks to kill all witnesses by dehydration. It's implied that this is entirely a delusional fantasy of his that mirrors those held by Walker.
- The Investigation Team in Persona 4 at first think Taro Namatame is one of these, due to his...unhinged behavior and his insistence that he's "saving" people. He isn't. He means "save" literally: he genuinely thinks he's protecting people from the real killer by kidnapping them and putting them into the TV world. He just doesn't realize it's the TV world that's killing them, or that he's playing directly into the killer's hands.
- The Order of the Stick:
- Miko starts out as a regular Knight Templar but descends into this trope as she becomes increasingly delusional. In the end, she is busy saving the world from imaginary threats and interpreting pretty much anything as signs that the gods are approving of whatever she is doing — ignoring the very real sign that they have stripped her of her paladin powers. She ends up making a misguided Heroic Sacrifice that saves the Big Bad from justice and condemns her people to A Fate Worse Than Death.
- Dwarfs as a society seem to have this regarding trees of all things. They consider them to be terrifying monsters that must be destroyed to protect people, even panicking if roots start to breach their mines. Note that because they live in a D&D fantasy universe, there are dangerous treelike monsters in existence, but dwarfs are just as frightened of ordinary trees.
- In The Simpsons episode "Much Apu About Nothing", the people of Springfield form an angry mob and demand the town government do something to protect them from "constant bear attacks." All because a total of one bear wandered into town, destroyed one mailbox, and was swiftly and painlessly taken down by Animal Control. Naturally, the mayor forms a "Bear Patrol" and passes the cost onto the taxpayers.
- South Park:
- Eric Cartman in general, but especially as The Coon in the Coon Trilogy, where he will maim anyone for his gain (including harming a small child for liking Mint Berry Crunch better than him) and rationalize it as a heroic action.
The Coon: I'm making the world a better place!
Mysterion: For you! You're making it a better place for you!
The Coon: [beat] Riiight, and that's what superheroes do.
- Several times, Al Gore is seen crusading against the imaginary monster "ManBearPig", a stand-in for Gore's real-life crusade against global warming. Later on, however, ManBearPig is revealed to be an actual threat to humanity and the kids are forced to apologize to Gore, representing the show's creators acknowledging their faults in regards to mocking him in the face of climate change.
- Eric Cartman in general, but especially as The Coon in the Coon Trilogy, where he will maim anyone for his gain (including harming a small child for liking Mint Berry Crunch better than him) and rationalize it as a heroic action.
- My Little Pony: Friendship Is Magic has an episode where Twilight receives a visit from her future self with a warning of some impending disaster. Unfortunately, future Twilight gets sucked back to the future before she can say what that disaster is, and so present Twilight goes through hell and high water to try and prevent it, whatever it may be. Turns out there was no disaster, and the warning was for present Twilight to not drive herself crazy trying to decipher an incomplete message from the future.
- In the Looney Tunes short "Stupor Duck", Daffy Duck portrays a superhero hunting for the terrorist mastermind Aardvark Ratnick. What he doesn't know is, Ratnick isn't real and is only a character in a soap opera. As a result, he "rescues" a building that is actually being torn down by a demolition crew, "saves" a ship from sinking that's actually a submarine, and otherwise causes problems instead of solving them.
- Zigzagged with Numbuh One on Codename: Kids Next Door. He plays this Trope straight sometimes; other times, it turns out he's pursuing No Mere Windmill. Out of the whole Section V crew, he is the most paranoid about adult conspiracies.
- Eliot Kid: Eliot and his friends are this in most episodes, fighting off threats that only exist in their imagination.
- Ed, Edd n Eddy: In "Ed Edd N Eddys Boo Haw Haw", after his mind is warped by a monster movie marathon, Ed hallucinates that he is "Lothar the Barbarian" and everyone in the Cul-de-sac is a monster sent by a trio of witches to attack the Eds. He then spends the entire episode bashing the brains out of all the innocent bystanders (except for Johnny the spider creature) he encounters.
- Milo Murphy's Law has a brief example in the form of Cavendish. Each time he and Dakota try to save the Pistachios, Milo shows up and their mission is thwarted. This causes Cavendish to believe that Milo is a time traveler from a rival faction and that he deliberately causes their mission to fail. All the while, Milo talks about how much he likes Cheese Fries and cheerfully adds "They're Fries, with cheese!".