In the first Yes! Pretty Cure 5movie, the Big Bad has the MacGuffin in hand... but it's not complete, so it can't grant any wishes. Blame Urara, who still had that last Pinky and hadn't put it in yet.
Carr Benedict in Allison And Lillia agrees to take sole credit for the history-changing discovery made by Allison and Wil, when he was only present because he'd been trying to shoot them. The newly-promoted Major Carr finds the resulting mass adulation and jealousy deeply uncomfortable. His reckless actions in the next adventure (which he secretly hopes will bring his rank down a notch or two) only cement his heroic reputation.
In the first chapter of Whistle!, the main character switches schools and is mistaken for a soccer star by his new team. He doesn't have the confidence to correct them, causing him to be outed embarrassingly when they actually make him play, and he's terrible.
Irresponsible Captain Tylor - While he does not really become celebrated (although he gets quite the reputation amongst the enemy), Justi Ueki Tylor does seem to hit both flavors often.
In Uchuu Kyoudai, Mutta accidentally foils a robbery and briefly becomes a celebrity.
Disney - Mickey's pal Goofy has been an accidental hero so often that it became a cliche in 1960s comics. Goofy would set out to engage in some hobby or sport, capture a small-time crook by mistake, and then use the inevitable reward money toward the hobby. Every. Single. Time.
An Archie comic had Jughead failing as a security guard until he tripped and fell on a guy who turned out to be a shoplifter.
The Avengers - Hardball was recruited into the Initiative when he used his powers to save a little girl from being hit by an armored car — at least, that's what it looked like to witnesses. In reality Hardball was trying to rob the armored car. The rescue was a coincidence. This is one of the first hints that Hardball is a bit too amoral for a superhero-in-training.
Quite often the Incredible Hulk isn't actually trying to do something heroic, but he often does a lot of good with his powers anyway.
Quantum And Woody's first case was an investigation into the murder of Ed Palmer's wife. They follow clues all around the world until they captured Terrence Magnum, a global financier with a stolen computer chip that could decrypt military codes. Unfortunately, he had nothing to do with the murder — Mrs. Palmer was killed by her husband, as the police had originally surmised.
The Valiant Little Tailor is one of the fairy tales recorded by The Brothers Grimm, in which a tailor's story of killing "seven with one blow" (that is, seven flies) accidentally gains him a reputation as a fearsome warrior, leading him into a series of deadly encounters with giants and other magical creatures. Disney adapted this story as a Mickey Mouse cartoon in 1938.
The Mariachi in El Mariachi came into town just to find a place to play music and get some cash. Instead, when his guitar case is switched with a guitar case full of weapons owned by an infamous hit man, the villains and the Distressed Damsel mistake him for the hit man. Dumb luck allows him to kill the hit squad sent after him, elevating him to legend status.
Though after the tragedy of the movie's end, the Mariachi would undergo a transformation over time into the gunslinging vengeance-driven Badass that we would see in Desperado, a figure more than worthy of the legend.
In Army of Darkness Ash both invokes and subverts this trope at different times.
Played with in the movie Accidental Hero (also known as simply Hero): the actual person who saves the people from a burning plane is a Jerk Ass who has one moment of decency (a plane crashes in front of him and he grudgingly helps the victims get out). The bum who (falsely) takes credit for said rescue is otherwise the kind of person you'd believe to be a hero and uses his reputation to help other people. There's enough gray area between them for the audience to decide which (or both) is the true hero.
Juan, one of the Villain Protagonists of Duck, You Sucker!, a Mexican highwayman/rapist/murderer, ended up becoming a revolutionary hero after knocking over a bank and inadvertently releasing the political prisoners being kept in its vaults. The gold deposits had been moved out of there months ago, and Sean, his "friend," neglected to mention that to him when helping him plan to "robbery."
In Star WarsThe Phantom Menace, Anakin Skywalker gets into Naboo fighter ship to avoid a firefight in a hanger on Naboo. After accidentally activating the autopilot, the ship flies to the scene of the space fight, where Anakin figures out how to turn off the auto pilot. In an effort to escape being blown up by federation fighters he flies the ship into the hanger bay of the enemy federation ship. After several robot droids notice him and start approaching his ship, he fires on them, destroying the droids. Conveniently, several of Anakin's missed shots at the droids hit a power system structure, which happens to be directly behind the droids. Anakin narrowly escapes the erupting federation ship, which is noticed by other Naboo fighters. "There's one of ours out of the hanger." After the federation ship is destroyed by Anakin's bad aim, the battle is over as without the command and control from the federation ship the attacking droids all shut down.
The heroes of the parody westerns The Paleface (Bob Hope) and The Shakiest Gun in the West (Don Knotts) are Accidental Hero material of the second variety. Both men succeed in "saving" a convoy of covered wagons, but the real heroes are their girlfriends (secretly US agents in disguise).
In Charlie Chaplin's Modern Times, Chaplin thwarts a prison break by dodging bullets and pummeling the escaping prisoners. But he only does so because earlier he'd unknowingly sprinkled cocaine all over his lunch that another prisoner had hidden in a salt shaker, and was completely high at that point.
Audrey, Wait!: The media latches on to Audrey as the subject of infamous Ear Worm and Breakup Song, "Audrey, Wait!", turning her into a celebrity for no real reason other than inspiring the song. Not "heroic" in the traditional sense, but Audrey uses the media attention to good ends.
Chronic (if pitiable) Villain Gollum in J. R. R. Tolkien's The Lord of the Rings is a peculiar example: in the book's climax, it is he who ultimately saves Middle-earth from utter disaster, by sheer chance. Although nobody appears to be celebrating him. In an interesting version of the trope, the event reflects favourably on several protagonists, including Frodo, Sam, Bilbo, Gandalf, Aragorn, Faramir and the Elves, who all indirectly allowed his final intervention because they had the decency to spare his life when they could have easily (and very understandably) executed him.
Harry Potter is credited with defeating Voldemort as a baby, when it was really his mother's love that saved Harry and destroyed Voldemort's body. Allowing Harry to grow up without all that pressure is one of the main reasons Dumbledore arranges for him to live with Muggle Foster Parents (even if said foster family went a little too far the other way.)
In Harry Potter And The Order Of The Phoenix, the nervous Ron is applauded for making a save with his foot during practice. When Harry mentions this right before the first match of the year, Ron tells him that he fell off the broom and kicked it accidentally. Harry quickly quips, "Well, a few more accidents like that and the match is in the bag."
In Warhammer 40000Sandy Mitchell's Commissar Ciaphas Cain, HERO OF THEIMPERIUM! has been doing this since practically day one of his career, where he was declared a hero for saving his future aide, by charging to protect him from a horde of Tyranids - when in reality, he was simply running from more, larger Tyranids in the other direction. Since then, a combination of his survival skills, extreme good luck, and diplomatic abilities has resulted in him getting out of one hairy situation after another, with his reputation as a HERO OF THE IMPERIUM snowballing. Eventually, just being on the same planet was enough to panic an Inquisitor gone bad into trying to kill him, multiple times.
Everything Rincewind ever did in the Discworld novels that didn't involve running away like his backside was on fire.
Except for the one time that he mans up, in Sourcery. But it's okay! The statue, as a reward, gets downgraded to a plaque, gets downgraded to a certificate, gets downgraded to a fine.
It's implied that although a coward he may be, Rincewind also grew up on the streets of Morpork - and Survived. Which is why he chose a half-brick in a sock as his weapon against the greatest Sourcerer to ever live.
As Lord Vetinari remarks in The Last Hero, "[T]he thing about saving the world, gentlemen and ladies, is that it inevitably includes whatever you happen to be standing on." One of Rincewind's enduring character traits is his willingness to "heroically" face almost certain death whenever the alternative is facing absolutely certain death.
There's an element of this in The Wonderful Wizard of Oz, after Dorothy's house squishes the Wicked Witch of the East, and it's the key to the plot. Without squishing the Wicked Witch of the East Dorothy would never have acquired the Silver/Ruby Slippers and incurred the wrath of the Wicked Witch of the West. Nor would the Wizard have assumed she was powerful enough to destroy the WWW and thus never would have sent her there.
In The Hitchhiker's Guide to the Galaxy, Arthur becomes a hero to a race of alien birds for showing them not to take any nonsense from their machines by throwing away a cup of revolting tea substitute a Nutrimatic device had given him.
Wise Old Bird: In a moment we realised the truth. Just because the little bitches liked us, it didn't mean to say that we had to like 'em back. And that night we rounded up every last one of the little creeps.
In the Warrior Cats graphic novel Rise of Scourge, we learn that Big Bad Scourge became the ruthless warlord he was in part by trying to live up to a reputation for toughness he got for beating up two dogs. One of these incidents was a complete fabrication and in the other the dog just got bored and wandered off while Scourge was yowling at him. Of course, Scourge apparently did kill a few dogs for real later.
During the war in Lois McMaster Bujold's Shards of Honor, Cordelia gets all the credit for killing Admiral Vorrutyer. She protests, but not too strongly, because she's protecting Sergeant Bothari, who would get court-martialled if his side knew he had done it.
In John Gardner's novel "The Liquidator" an allied soldier mishandles his sidearm and kills two men. Fortunately for him they are both German agents. This seen by the Allied agent they were trying to kill who mistakes his terror stricken gaze as stone cold killer face. The agent later recruits the soldier as an assassin.
Subverted in All-American Girl, where the main character believes she's this but, in fact, she really did do something heroic.
Live Action TV
In the Firefly episode "Jaynestown," Jayne is idolized by the citizens of a small town who herald him as the hero who robbed their oppressor and gave them the money. What the locals do not know is that the robbery was just that: a robbery. Jayne had every intention of keeping the money, but his ship was damaged and he had to throw the money out the window in order to escape. In fact, he was so determined to keep that money that he actually threw his partner out of the ship first. The spurned partner returns, minus an eye, and reveals the sordid truth, but this does not stop a local man from taking a shotgun blast meant for Jayne. There's even a song that the locals composed in celebration of his "heroics," an excerpt of which can be found on the quote page.
Jayne also denounces heroes in and of themselves shortly afterwards, saying there's no people like that. "There's just people like me."
Star Trek: Deep Space Nine has the episode "The Homecoming": the Bajoran Li Nalas was hailed a legendary hero after slaying a powerful Cardassian warrior in an epic contest of strength and skill. The truth is that Li Nalas caught the man by surprise——the Cardassian had just finished bathing and was clad only in his underwear, and the impression of a struggle only came about because the Cardassian collapsed on top of Li Nalas after he had been shot. Though he wanted to reveal the truth, he was convinced by Benjamin Sisko that his "deeds" inspired others and, even if it never really happened the way people said, he was the hero that the people needed.
Another Deep Space Nine episode, "Nor the Battle to the Strong", has Jake Sisko: a civilian, aspiring novelist and part-time journalist. While on a besieged planet, Jake defended a field hospital by causing a minor cave-in, killing two Klingon invaders and sealing the entrance. Except that it was all an accident, he was panicking and shooting blindly, and the results were extraordinary luck for him. He freely admitted, however, that he was acting on fear and only trying to stay alive. He even wrote a truthful account of it for publication. He may not be a hero, but he's a very conscientious journalist.
Lost: in "Through the Looking Glass," Jack is called a hero for pulling a woman and her son from a burning car. When the woman regains consciousness, she reveals that the reason she crashed was she was looking at Jack, who was about to jump off a bridge at the time.*
The Irony being that even though he was the one to pull them from the car, it was her who saved him by being there right at that moment.
F Troop "The end of the Civil War was near; When quite accidentally; A hero who sneezed abruptly seized; Retreat and reversed it to victory."
In an episode of Frasier, Bulldog enjoys this status when he grabs Roz and spins her away from danger when their coffee shop hangout is attacked by a gunman. In actuality, Bulldog thinks that someone pulling out his wallet is the gunman and spins Roz towards him, using her as a human shield. The rest of the episode features Bulldog being lauded with praise for being a hero while Frasier tries to convince him to come clean - starting with simply asking him and escalating into more and more elaborate attempts to guilt-trip him. Of course, him being Bulldog, none of this works. Things finally return to normal when Frasier's dad yells "He's got a gun!" at a banquet in Bulldog's honor, causing him to repeat his actions, whereupon he is berated by all the guests there. It turns out, however, that Frasier's dad doesn't really care about right and wrong in this case, he just wanted Frasier to shut up about it.
In an episode of Friends, the male characters go to a seedy part of town with Phoebe's then-boyfriend Gary. While there, what sounds like a gunshot is heard, and Joey jumps on top of Ross, apparently protecting him with his body. He's hailed as a hero, even though it turns out it was just a car backfiring, because he didn't know it wasn't a gunshot. When Chandler gets upset because Joey protected Ross instead of him, however, Joey admits he was actually protecting a sandwich.
yeah a hero sandwich.
Ralph Hinkley/Hanley from Greatest American Hero was this up until the end of the series when his character was completely derailed and he became famous for being a super-hero. Earlier in the series, with rare exceptions, he avoided the hero role that was thrust upon him.
In an episode of Good Luck Charlie, Teddy ditches class to prove that she is not a goody-goody, which she is being called by everyone at school. However, when she is there she stops a pickpocket and is awarded a medal of honor in school the next day, and the class cheers her on by calling out "GG", short for goody-goody.
In the Police Squad! episode The Butler Did It (a.k.a. A Bird In The Hand), a gunman holds three police officers hostage in a room at a police station. Suddenly, Frank Drebin opens the door, hitting the gunman and allowing the police officers to apprehend him.
Ed Hocken: Nice work, Frank.
Frank Drebin: (confused) What?
Beetle Bailey: When Beetle of all people receives a medal for being an exemplary worker. It starts when he gives his usual kind of lip ("I could do that, if I wanted to") to Sarge "asking" him to clean up some graffiti. Sarge gets angry and gives a violence-laden order for him to want to do it, then. When he's cleaning the wall, Killer happens by and asks why he's doing it, to which Beetle replies with angry sarcasm that it's because he wants to. The General also happens to walk by and is impressed by this dedication.
Leisure Suit Larry goes looking for love (in several wrong places). Larry Laffer meets a latin american woman at a music store, and tries to talk in Spanish with her. Problem is, he took Spanish at high school, and don't understand the girl... but the girl thought that his badly spoken stock quotes were secret salutes, and thought he was the Soviet agent she was waiting. She gives him a Peruvian onlunk with a hidden chip for the evil Dr. Nonookee; Larry, incapable to understand, thought it was a gift. And so, Larry is chased around by several soviet spies and agents of the KGB, without even being aware of it (that is, unless they capture him, and dies). Finally, the onlunk is broken when Larry falls in the middle of a jungle. Poor Larry: he saved the world, and the only thing he received for it was a bush with killer bees...
The Boy just wanted to cut some tall grass...though you do find out later that he comes from a heroic lineage.
Whatever party you choose in Seiken Densetsu 3, the fairy just picks them to bond with because they happened to be there.
In Paladin's Quest, Chezni starts his journey because he was duped by his "friend" Duke, actually Zaygos, the Emperor of the Southern continent, into activating Dal Gren.
In Chrono Trigger, the "Legendary Hero" Tata stumbled across the Hero Medallion after Frog decided to throw it away.
Kevin Kolton from Evil Plan wasn't trying to do anything heroic with the supervillian's telekinesis chip. He accidentally installed it by falling asleep in class.
Megas XLR did this. Naturally, the beautiful anime-inspired (read "a complete parody of Sailor Moon") residents intended to put Jamie up against a powerful monster without letting him get in a word of objection edgewise. Or briefing him on what would kill off a monster, and what would merely appear to kill it, leaving it to come back stronger in a couple hours. Considering that the show's premise is "Giant Mecha lands in the yard of American Teenager, he uses it to save world." (on drugs), nobody should be surprised.
The Simpsons episode "Homer Defined" had Homer save the town from nuclear doom by using eeny-meeny-miney to find the right button. He is then lauded as a national hero. He later manages to recreate his blunder, but the townsfolk figure out he had no idea what he was doing, and his "reward" this time is inspiring the term "pulling a Homer".
Similarly, in "Little Big Girl" Bart accidentally puts out a fire when using fire extinguishers to propel himself forward along the road... his intention was just a cheap thrill, but the material from said fire extinguishers put out a fire that he encountered along the way.
In the South Park episode "Roger Ebert Should Lay off the Fatty Foods", Cartman, furious that no-one saw him on TV, knocks over the mind controlling Planetarium projector in a fit of rage, inadvertantly saving Stan and Kyle, and wiping the mind of the Planetarium owner.
In an episode of Batman The Animated Series, a very small-time thug, "Sid the Squid," working as a lookout somehow managed to accidentally "kill" Batman, which makes him a hero and a big-shot to Gotham City's underground. It also earned him Joker's wrath, however. Batman is actually still alive, saving Sid and collared the Joker; Sid gets sent to a big prison outside of Gotham City limits, where he is still treated as a hero for almost killing Batman—and making both Rupert Thorne and the Joker look like fools.
This is the only reason anyone in Inspector Gadget accepts the title character as an Inspector. However, he's so clueless that he believes the hype and never realizes for himself that he's not really the hero. Then again, his bumbling often genuinely does help save the day, usually in a Spanner in the Works fashion.
Archie Comics: The superhero Bob Phantom created an identity in order to get close to superheroes and learn enough about them for his expose book. In his first appearance, however, he is mistaken for a genuine superhero, and, worse still, ends up helping another hero save the day!
Duck Dodgers is this to the Martian Queen (and only the Martian Queen). Whether it's a well-timed teleporter malfunction, or bending over at just the right moment, whenever he's around her, circumstances conspire to make him look like a Bad Ass.
In one U.S. Acres segment of Garfield and Friends, the normally cowardly Wade accidentally saves the day, and as a result becomes rather arrogant for his so-called heroism — until, of course, he is faced with a situation where he must save the day again.
In an episode of Recess, TJ gets a black eye and won't tell anyone how he got it. The other kids convince themselves that he got it performing some heroic feat or other and is just too modest to admit it. After initial protests TJ quickly starts enjoying the hero life, even getting a parade in his honour. When he's asked to tell the tale of how he got his black eye at the parade, however, his conscience finally kicks in and he admits the truth - He was square-dancing, and his partner knocked into him.
One of the early episodes of Arthur has a Cat Up a Tree leap into Buster's arms to eat his ice cream, due to it having fish, thus becoming a hero. He lets the hero stuff go to his head and Arthur and friends decide recreate the scenario via robotic cat to prove he is no hero. It succeeds, much to the disappointment of Buster, but then he (intentionally) saves Arthur and Francine from a runaway piano. Here We Go Again.
This happened to Doofenshmirtz in an episode of Phineas and Ferb when he accidentally saved a falling kitten when he tripped coming out of the store. As a result, everyone (including his enemies) believes him to be defecting to the good side. He even attempted to get rid of the news footage of the event to save his reputation.
A blind Peter becomes one in Family Guy, when he pulls Horace out of the Drunken Clam without knowing it was on fire.
Tom Tucker: Here comes the blind hero now. Tell me sir, how were you able to summon up the courage to enter that burning building?
Peter: That freakin' place was on fire!?
The entire series Hong Kong Phooey was built on this trope. In earlier episodes, the titular character often lucked into his heroic acts, and in later episodes, his faithful pet cat was responsible for orchestrating the events that led to his heroism. All the while, the entire cast, the titular character included, believe him to be a skilled superhero.
In Fragebogen, Ernst von Salomon relates that in the concentration camp where the Americans (yes, the Americans) interned him as a "security threat", he was informed that the general everyone was kowtowing to was the victor of Crailsheim. You never heard of the Battle of Crailsheim? It was the last German victory. In Crusade in Europe, Eisenhower noted that "...we occupied Crailsheim, but were forced to withdraw by unexpectedly strong resistance." The real story: the general, in his command tank, was cut off from his unit in the darkness. He finally found an armored column and traveled with it all night, before finding that it was an American column. He tried to slip off quietly (insofar as possible in a tank), but was spotted. So he opened fire with everything he had. The Americans heard firing, thought the Germans had outflanked them and were counterattacking from the rear, and pulled out of Crailshem. "Proving that a general without his command can be just as useful as a lance corporal."