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[[quoteright:350:[[VideoGame/MetroidZeroMission http://static.tvtropes.org/pmwiki/pub/images/SamusGirl_3978.png]]]]
[[caption-width-right:350:Samus's gender: a {{late arrival spoiler}} since 1986!]]

->'''Kid Icarus:''' Gosh-a-cus, Princess Lana! [[{{Franchise/Metroid}} Samus]] is super-duper-a-cus!\\
'''Lana:''' Well... Samus is a veteran of many impossible missions! Samus is a super-powered cyborg! Samus is the greatest space hunter in the Galactic Federation! ''[Samus removes her helmet]'' Samus is a... woman?!?!\\
'''Kevin:''' Whew! You sure are!
-->-- ''WesternAnimation/CaptainNTheGameMaster'' comic story "Money Changes Everything"

Samus Is a Girl is when an ActionGirl is well established as heroic, or otherwise badass before the first hint that she's female. Whether the initial lack of discernible sex is caused by bulky armor, baggy robes, [[WholesomeCrossdresser subtler deliberate deceptions]], shapeshifting, or even just the camera refusing to give a clear shot of any distinctly female parts of her, it's still Samus Is a Girl. Heck, a tank with a chick inside would count. Having a TomboyishName or GenderBlenderName helps as well. In fact, you can expect this trope to happen pretty much every time you hear a gender-neutral name like "Alex" and it's not the name of an already established male character.

Oftentimes, Alice will only wear the form-concealing outfit during her introduction. Afterwards, it may end up getting lost or destroyed, and thereafter she wears something a little less ambiguous. Sometimes, she just stops on her own.

This is notably harder to pull off in some languages--those that don't use gender-neutral descriptors that much (on the other hand, it's ''very'' easy to pull off with some foreign characters, since quite a few Japanese and African names can be assigned to either gender). It's one thing to say Samus is a bounty hunter, but when your language demands that if the gender is known, this should be bounty huntress, characters that ''do'' know about Samus's gender and just don't care to elaborate to the listener couldn't just call her a bounty hunter without stretching suspension of disbelief. However, in English speaking countries, it is becoming more common to use the "masculine" or "gender-neutral" term when referring to women. For example, female actors are often referred to as actors rather than as actresses. It's one thing to trick the viewers by clever terminology, but when you completely break your language to do it, the effect becomes not so much "Hey, that's right, the gender was never actually mentioned!", but "Um... so the character who was referred to as male by others who knew she was female all the time was actually female. Huh?"

Perhaps nobody mentioned her gender because YouDidntAsk. Or because she's just one among a whole BadassArmy, so nobody paid attention specifically to her. Or because she's a complete stranger that nobody had seen before. Maybe she is a VoiceWithAnInternetConnection, and no one has ever seen her in person.

See TheFaceless and the {{Hackette}}, a SubTrope. Contrast UnsettlingGenderReveal (where characters/some audience members are physically/romantically attracted to this person in their mistaken gender), SweetPollyOliver (Samus Is a Girl from a viewpoint that already knows she's female) and ViewerGenderConfusion (where the audience, not the characters, don't know what gender Pat is). See also GeekyTurnOn, which is sometimes related to this. FemaleMonsterSurprise is a similar trope, but with a monster. May involve GenderMisdirection. Not AlwaysFemale, but usually, due to the typical gender roles where everyone assumes the action hero is a dude; the cast being composed of Amazons is one example where this may be reversed.

''Please, don't bother with the spoiler tags here. The name of this trope is a pretty good reason why this should not be.''



[[folder:Trope Namer]]
* Named for Samus Aran from ''{{VideoGame/Metroid}}''. In the [[VideoGame/{{Metroid1}} first game]], the player doesn't learn she's female until after guiding her through an army of alien baddies. Most games since have followed in the tradition of showing her out of armor only if you beat the game ''and'' fulfill certain conditions, but they still do play with the trope in a number of different ways.
* The ''VideoGame/MetroidPrimeTrilogy'', however, gives her a rather feminine figure considering she's in armor, shows her eyes through her visor, and has the Space Pirates describe her as a female in their log entries. ''VideoGame/MetroidPrime3Corruption'' even shows her as a woman at the ''start'' of the game.
* ''VideoGame/MetroidOtherM'' completely throws this away, because you see Samus without her suit in the opening sequence, in many cutscenes (sometimes this is just a shot of her face through her visor), and in the death sequence.
* The password [[http://metroid.wikia.com/wiki/Justin_Bailey "Justin Bailey"]] entered in the first game, will start Samus near the end of the game, with no armor on (visually; gameplay is unaffected). One of the most famous cheats in video games, it's also notable for ''[[GoodBadBugs not being intentional]]''. The name's effectiveness is ultimately a fluke caused by the "loose" password system.
* The death sequences in ''VideoGame/SuperMetroid'', ''VideoGame/MetroidFusion'', ''VideoGame/MetroidZeroMission'', and ''VideoGame/MetroidSamusReturns'' also have her armor shattering and reveal her form underneath. Plus, ''[[VideoGame/SuperSmashBros Super Smash Bros. Melee]]'' gives her a sleek version of the Varia Suit.
* In the original game, even the ''manual'' refers to Samus as male. The developers only came to the decision to make her female about midway through the production process, when one of them casually remarked that it would be really funny to get to the end and discover she was a girl all along. Possibly one of the greatest ThrowItIn moments in video game history.
* The manual of ''VideoGame/MetroidIIReturnOfSamus'', however, uses "she" throughout. A literal case of AllThereInTheManual, only confirmed in-game by the best ending.
* In ''Zero Mission'', you get a visor shot right before the game begins, but if you're not paying attention, you'll miss it. Hilarious, given that ''Zero Mission'' is a redone and updated version of the original game.
* In the ''Franchise/{{Halo}}''[=/=]''Metroid'' crossover ''WebAnimation/{{Haloid}}'', this happens not only with Samus, but with our favorite Spartan as well. Wait--surprise! That's not Master Chief, but Nicole-458, a female Spartan who appeared in the ''VideoGame/DeadOrAlive'' games (even though there's no canon on ''what'' Nicole looks like). She ends up pulling this trope on Samus herself, making ''Haloid'' a double whammy.
* Played with a little bit in ''[[VideoGame/SuperSmashBros Super Smash Bros. Brawl]]'', if the player fights her as [[VideoGame/MetalGear Solid Snake]] on Shadow Moses Island. In his Codec transmission, Snake remarks to Otacon that he's fighting "a woman in a power suit." Otacon is baffled as to how Snake can possibly know she's a woman. Snake's comments in this transmission, and in the one he makes if he fights her in her Zero Suit, are the main reason Snake/Samus has become a popular ship among the fans. Hint: he figured it out by watching how she walks [[MaleGaze and checking out the anatomy involved]]. This is a shout out to how the player finds Meryl Silverburgh in disguise in ''VideoGame/MetalGearSolid''--exaggerated hip sway. These conversations may also be subtle foreshadowing of the Power-Suited AmazonBrigade that would appear in ''VideoGame/MetalGearSolid4''. It's not the only thing Hideo Kojima foreshadowed in that game.
* In ''Super Smash Bros. Melee'', one of the events is called "Girl Power" and has you fight Samus, Zelda and Peach. If you didn't know Samus was a girl, you would be surprised to see her there, since Samus never takes off her suit in normal gameplay. The manual does not refer to Samus as a woman and her first trophy avoids using pronouns.
* When ''Metroid'' first came out in the '80s, Nintendo of America ran a ''Metroid'' art contest in their magazine "the Nintendo Fun Club News" (a precursor to ''Magazine/NintendoPower''). All the winners who had Samus unmasked in their art depicted her as a man. [[http://math.utoledo.edu/~dgajews/sw35/NFCN/Metroid_Art_Contest_small.jpg This is the art in question.]] Notice the one that was tied for 4th. This was obviously based off an ending in the game, in which Samus' face was the only thing that was revealed. Thanks to the 8-bit graphics, it was ''still'' impossible to tell whether or not Samus was a girl. One could easily interpret that the person in the suit was simply a guy with EightiesHair. Apparently, the artists settled for that notion. Seems that the judges of the art didn't do the research and did the same. Either that or Nintendo knew beforehand and decided to make the judges disqualify the entries that depicted Samus as a female in order to keep the twist a secret.
* In the ''WesternAnimation/CaptainNTheGameMaster'' comics in the ''ComicBook/NintendoComicsSystem'', Samus was a regular character, and in her first appearance, it surprised the regulars from the cartoon when she unmasked for the first time. [[http://thepunkeffect.com/wp-content/uploads/2013/05/3a223d2c97f405bdd789d3bc96da8ec7bffa1250.png The scene in question is quoted above.]]
* American ''Metroid'' commercials avoided referring to Samus by pronouns for years. It wasn't until ''Metroid Zero Mission'' that Samus' gender was alluded to in an ad.
* Due to a combination of this trope and ProtagonistTitleFallacy, there is a [[MemeticMutation meme]] about the ''Metroid'' series where people refer to Samus in and out of her armour as two different people: the male hero Metroid and his girlfriend Samus.

* The infamous [[spoiler: "[=TheLegend27=]"]] from ''VideoGame/GameOfWarFireAge'' ads.[[https://www.youtube.com/watch?v=WCiDfm9i9rQ]]
* Used in a Finnish ad for the army, where paratroopers are making a training landing in a forest and ''It's Raining Men'' plays. The song cuts when the troopers remove their helmets, revealing that they are all women.
* Commercial for a high-grade beer shows the hands of the brewmaster at work, as the narrator praises the skill of those hands. At the end, the narrator says that they're focusing on the brewmaster's hands because she's not a particularly-attractive woman.
* In a 2016 Campbell's Soup ad, a child is playing around a house in a Spider-Man costume. Before taking a sip of the soup, the child takes off the mask to reveal that she's a girl.
* [[http://www.redbullusa.com/cs/Satellite/en_US/001242981626958 This Red Bull ad]], the biker is a woman. And deaf.
* There's an ad for an airline company with a couple walking through the airport with their child, who is wearing a full spacesuit. When they get to boarding, one of the attendants comments on the little astronaut wannabe, [[CompressedHair who takes off her helmet.]] The final scene shows her playing with her toy rocketship on the beach, wearing the helmet again with a bathing suit.

[[folder:{{Anime}} and {{Manga}}]]
* The ''Anime/HaloLegends'' anthology does this a couple of times with the [=Spartan-IIs=], due to them being 7-foot-tall {{Super Soldier}}s clad head-to-toe in PoweredArmor:
** "The Babysitter" uses this trope for Spartan-II sniper Cal-141, since she doesn't even ''speak'' for most of the short.
** Done again in "Homecoming", where Spartan-II Daisy-023, after saving a platoon from a Covenant ambush, is revealed to be a girl when she removes her helmet. [[http://www.halopedia.org/File:Homecoming_Daisy-023_Harvest.jpg The helmet even kind of looks like Samus's.]]
* Marlene in ''Anime/BlueGender''. Yuji is her "Bob."
** He's more surprised by the fact that she's human than the fact that she's female. Waking up in the middle of a BugWar and seeing nothing but NightmareFuel for a solid 5 minutes can do that to you.
* ''Manga/JoJosBizarreAdventure'':
** In Part 2, ''[[Manga/JojosBizarreAdventureBattleTendency Battle Tendency]]'', Joseph Joestar and Caesar go to meet Caesar's mentor. When Joseph finally mets her, she is initially fully dressed and her face is concealed, and he thinks she must be a man... until she reveals her face.
** In Part 7, ''[[Manga/JojosBizarreAdventureSteelBallRun Steel Ball Run]]'', Hot Pants was initially assumed to be a guy, and drawn with masculine features like broad shoulders and square chin. We find out she's a woman at the end of her introductory arc. From that point on, she began to be drawn in a more feminine style.
** In Part 8, ''[[Manga/JojosBizarreAdventureJoJolion JoJolion]]'', Josuke is attacked by Going Underground/Born This Way, a Stand that looks like a man riding a motorcycle. Turns out the user is Kyou Nijimura, the Higashikata family maid.
* Rei in the manga version of ''Anime/NeonGenesisEvangelion'' when she's still inside the Eva. [[FogOfWar In the confusion of the battle]], Shinji can't tell if anyone ''is'' inside the Eva (Rei's name comes up, but that seems to be a thought bubble rather than spoken dialogue on Misato's part). Shinji cries out (in the English translation), "Our guy's getting clobbered!" But when he gets to NERV headquarters, he still seems to think he was saved by a robot. At any rate, as soon as the reader -- and, a few panels later, Shinji -- actually ''[[TheReveal sees]]'' Rei, it's clear she's a BandageBabe -- along with all sorts of other types of {{fanservice}} / FanDisservice.
** Carefully averted in ''Anime/RebuildOfEvangelion 2.0'' with Asuka, who arrives in Unit 02 to fight the Angel. Shinji had never seen her or her Eva before but when he does comment on the battle, he doesn't use any third-person pronouns in either the Japanese original or the English dub.
* In ''{{Manga/Berserk}}'' Guts doesn't realize that Casca who is in full medieval knight armor is woman until he knocks off her helmet.
** Later at a formal celebration Guts is approached Casca now dressed in, [[IncrediblyLamePun well, a dress]], despite knowing very well that she's a woman, Guts is awfully surprised to see her looking like one, likely used to her being one of the guys.
** Even later when the Hawks plan to rescue Griffith their guide is none other then Princess Charlotte who admits not realizing that she was a woman the first time they meet (much to Guts and Judeau's amusement).
* When most people hear of the assassin ''Anime/{{Noir}}'', they assume it to the be the codename for a ''male'' assassin, as opposed to the fact that it is actually ''two'' girls.
** Especially ironic, since eventually it's revealed that Noir in fact originally referred to two female killers as long as thousand years ago.
* In the ''Manga/GiantRobo'' [[OriginalVideoAnimation OVAs]], ActionGirl[=/=]CoolBigSis Ginrei first appears in disguise as a [[CoolMask masked]] BadassLongcoat to rescue Dr. Shizuma -- for all of a minute, before [[FlungClothing suddenly changing]] into her trademark Chinese dress, and never using the "Iron Mask" disguise for the rest of the series.
* Cagalli Yula Athha of ''[[Anime/MobileSuitGundamSeed Gundam SEED]]'''s [[{{Tomboy}} tomboyish personality]] and androgynous clothing originally fools both Kira and Athrun into thinking she is a boy. Her gender confusion is also an in-joke to the viewers, as her voice actress Creator/NaomiShindo usually voices young boys.
* ''Manga/RanmaOneHalf'':
** Ranma's UnluckyChildhoodFriend Ukyō is the series foremost example. Having met her at a very young age, Ranma always believed her to be another boy; after a bitter grudge match in which she forces him to fight "seriously," he is stunned to discover she is actually a girl. HilarityEnsues:
---> '''Ranma:''' Since when are you...\\
'''Ukyō:''' ...a girl? Since I was born, idiot.\\
''[Ranma pours hot water on her]''\\
'''Ukyō:''' Ow! Hot! Hot! Hot! ''[punches Ranma]'' Why the heck did you do that?!\\
'''Ranma:''' Hey, you didn't turn into a man!?\\
'''Ukyō:''' What's that supposed to mean? Listen up and well! I am one hundred percent woman!!!
** Exemplified and subverted ''again'' by the character Herb. When the tall, dark, powerful stranger who handily defeats is shown to be a woman, the cast reacts with surprise and shock. However, the subversion comes as it turns out that Herb is the ''Prince'' of the Musk Dynasty, who, having fallen into the same cursed spring as Ranma, also turns into a woman.
** This is then inverted by [[DudeLooksLikeALady Konatsu]] and [[MasterOfDisguise Tsubasa]], [[WholesomeCrossdresser Ukyou's]] would-be suitors who ''everyone'' (including the audience) believed to be girls, right up until the very final page of their introductory story arcs -- when [[ClothingDamage their outfits]] are destroyed, one way or another.
* In ''Manga/{{Bleach}}'', (read only if you've seen Episode 41 or read Chapter 116) Yoruichi is a more long and drawn out version of this; as long as she remains in cat form, everyone assumes she's a man. In the manga, this was just an assumption on the part of the reader. The anime is more deceptive; they gave cat-Yoruichi a really masculine-sounding voice. It doesn't help that she has the speech patterns of an old man. Cat-Yoruichi is supposed to sound masculine; in the manga, she tells Ichigo that most people who only know her as a cat think she's male because of her voice. HilarityEnsues when she reveals that she is a girl.
* In the anime ''Manga/{{Bastard}}'' Arshes Nei was shown at first as a figure in full plate and rather bulky armor, which made impossible to tell that the character within that armor was, in fact, a slender female.
* Mukuro from ''Manga/YuYuHakusho''. She even disguises her voice and covers her face when she is first introduced. She also refers to herself with the ''very'' masculine pronoun "ore" in Japanese, and, believe it or not, Hiei is her Bob.
* One episode of ''Anime/ExcelSaga'' concerns a mysterious masked man with a masculine voice. He and Nabeshin have a lot of HoYay, which Excel comments on -- and then the mask is removed, showing a beautiful blond woman. [[RuleOfFunny Still with a masculine voice.]]
* A bit of a drawn-out occurrence appears in ''Manga/KatekyoHitmanReborn''. It is pretty much impossible to tell I-pin's gender, since she is a baby... Then she gets hit with the 10-year Bazooka. No romance (again, baby) but she ''does'' spend a lot of time with Lambo.
* Haruka in ''Anime/SailorMoon'', although there's no romance arc beyond her flirting with Usagi for the fun of it; she's already taken... by a woman, which helped hide her gender. Though due the fact that she appeared in the anime in her Senshi form before the reveal at the end of the episode introducing her, viewers are not as shocked as the characters. (It should be noted that before this episode, Uranus and Neptune DID show up in senshi form, but all the viewer was shown was a silhouette and the credits only listed them as "Mysterious Senshi 1 and 2". Also, for the first few Uranus and Neptune appearances in the original [[Manga/SailorMoon manga]], they were perceived not as two mysterious senshi, but as a mysterious senshi/Tuxedo Mask pair; and Haruka's flirting with Usagi was much heavier. It wasn't until after they joined with the other senshi that Uranus was perceived as a woman rather than a man.
* ''Manga/FullmetalAlchemist'':
** When Ed uses alchemy to destroy Lan Fan's mask in their fight, he's so shocked to see she's a girl that she's able to both destroy his automail arm and drop a bomb before he can react. Subverted the subtrope by not becoming Ed's love interest at all. In fact, she [[BodyguardCrush already has her own]] (there was a brief, mostly-played-for-laughs ShipTease between Lan Fan's love interest and Ed's, though).
** Major General Olivier Mira Armstrong. When Alex first mentions her she could have been a male as well, especially because her first name ''is'' [[GenderBlenderName a male name]]. Also, the "preview" image of her for the next chapter/episode in both the manga and anime is [[http://static.tvtropes.org/pmwiki/pub/images/fullmetal_alchemist_32_large_14.jpg ambiguous]].
* Yellow in ''Manga/PokemonAdventures''. Funnily enough, by the time of the reveal the only ones shocked by it are Red, Crystal, and later Gold. Red actually met her prior to formally meeting her however it's unknown if he ever finds out the girl he rescued was Yellow.
* ''Anime/{{Pokemon}}'':
** Kidd Summers at the start of the ''Anime/{{Pokemon}}'' movie: "Lucario and the Mystery of Mew", literally in armor. Semi-justified by the fact that ''everyone'' at the festival is in quasi-medieval costume.
** Anabel and Angie are both tomboys who Ash mistook for boys. Incidentally, they both end up developing a crush on Ash.
** Zoroark turns out to be female in the movie.
** [[TheOnlyOneAllowedToDefeatYou Georgia's]] Pawniard/Bisharp, despite being voiced by a man, is revealed to be female in her debut episode.
** This happened to Jessie twice. She thought her Yanmega and Pumpkaboo were both male.
* Due to the voice acting in the dub, German viewers often thought ''Anime/DigimonTamers'''s Renamon was supposed to be "male" (or at least gender-neutral -- it's a somewhat deliberately enigmatic digital lifeform in what's arguably a kids' show, after all). Which makes the final form a bit of a surprise.
** Plenty of people were caught off guard when Cutemon in ''Anime/DigimonXrosWars'' yelled that he was a boy around the middle of the series. Twisted even further in the dub -- he's voiced by a male and ''still'' sounds adorable!
* Parodied in ''SteelFistRiku''. Chikara Toudou arrives to challenge Riku's father, but since he's not around, he decides to challenge the "son", Riku, instead. At this point, Riku has her chest bound flat, so it's understandable. But then, Riku tells him she's a girl, and he accuses her of pretending to try and get out of the fight. Then, during the fight, he notices the bump under Riku's shirt... and thinks "he" is concealing a weapon there. He finally gets it after he grabs her breast.
* Odd variation in the ''Manga/MahouSenseiNegima'' manga: Earlier in the manga we met Paio Zi, a member of a group of bounty hunters pursuing Nodoka had a rather... "healthy" appreciation for [[strike:breasts]] boobies that bordered on the obsessive. Most readers found this character ''quite'' [[DudeNotFunny disturbing]]... until a recent chapter mostly [[FuroScene set in a bathhouse]], where the hunters are encountered again under peaceful circumstances, and Paio is revealed to be a girl, who proceeds to SkinshipGrope the hell out of pretty much everybody within reach (and she moves ''fast''), to the amusement of the fans. This comes across as a bit of a DoubleStandard, but she's really a lot less threatening without her fighting costume, which is rather monstrous and effectively ''quadruples'' (at least!) her body mass. Compare her [[http://www.onemanga.com/Mahou_Sensei_Negima!/218/06/ in costume]] (Commanding the tentacled worm) with her [[http://www.onemanga.com/Mahou_Sensei_Negima!/235/07/ out of it]] (Furo, remember? so may not be Work Safe).
* EnigmaticMinion Masquerade of ''Manga/{{Bakugan}}'' is actually Alice. She uses her StatOVision {{Sinister|Shades}} {{Mask|Power}} to transform.
* Noi of ''Manga/{{Dorohedoro}}'' does this in the first volume. She's one of the numerous masked badasses of the show; taller, bulkier and probably stronger than the entire male cast.
* Stir from ''Manga/KingOfBanditJing'' does this. She shows up in a full-plate armor to participate a gladiator duel. Everyone assumes she's a guy (as all the other participants were males), and were extremely surprised when her mask broke.
* In ''[[Anime/RevolutionaryGirlUtena Adolescence of Utena]]'', Saionji cuts Utena's shirt in their duel, leading to the following exchange:
-->'''Saionji:''' You're a girl?\\
'''Utena:''' [[YouNeverAsked I don't remember saying I was a boy!]]
* In the ''[[VideoGame/DragonQuest Dragon Warrior]]'' anime, [[ActionGirl Daisy]] saves [[TheHero Abel's]] hide a few times before he finds out she is a girl.
* ''Manga/FistOfTheNorthStar'':
** has this pulled off by the Last General of Nanto, who dresses like a fearsome warlord. Once the helmet comes off though, the General is revealed to be none other than Yuria, who was presumed dead at the time.
** A [[EstablishingCharacterMoment badass]] inversion was used in Rei's debut. You see a woman in a pink cloak being harassed by thugs. You think a badass martial artist will jump in and save the day. But the "woman" in the pink cloak turns out to be martial arts badass Rei in disguise, luring the thugs to him.
* Happens twice in the Manga/GetterRobo series:
** In Getter Robo Armageddon ,at the beginning of the series the kid is daughter of Dr.Saotome initially using boy's clothing. After missile fall to Earth events, Genki Saotome is adopted by Benkei and revealed that he is a girl and having her name changed to Kei Kuruma.
** Raikou Minamoto in New Getter Robo, who is revealed to be a woman only after Ryoma tackles her and [[AccidentalPervert ends up grabbing a handful]].
* Reversed in ''Manga/LiarGame'' in the second round where the seemingly innocent "Yuji" is revealed to be the cross dressing Mr. X.
* ''Manga/OuranHighSchoolHostClub'': Haruhi, if you watch the first episode [[ItWasHisSled unspoiled]], which is pretty much impossible nowadays.
* ''Anime/GlassFleet'' combined this with ViewerGenderConfusion because Michel had a female voice actor. The big reveal isn't until episode seven. Afterwards, her style of dress does not change.
* ''Anime/YuGiOhGX'': Rei initially disguised herself as a boy, but during her introductory episode, she turns out to be a girl. She pulls this off again during her second appearance, but later embraces her feminity (sort of) when she enters Duel Academia for real.
* In ''Anime/YuGiOh5Ds'', the helmeted D-Wheeler shown in the third intro sequence turns out to be a blond woman named Sherry. (Yusei doesn't ''truly'' realize she's a woman until the end of the first part of the two-part episode, but even before then, the cards she uses gives him and the viewers a clue that his opponent is a woman; mostly female monsters with a LadyOfWar theme, like Sherry herself, and flower-themed Trap Cards.)
* ''Anime/YuGiOhArcV'': While not revealed in-universe, the OCG released human versions of the Four Heavenly Dragons, revealing the fact that Clear Wing Synchro Dragon is actually female.
** Reira Akaba. The Japanese version has characters refer to them with gender-neutral pronouns, and the character wears a hoodie and hat to cover her hair, making her look like a boy. The dub refers to her as male, but gives her a gender-neutral name, ''Riley.'' Both fans and characters assumed Reira to be a boy, until TheReveal later on, when she takes off her hat and hoodie, revealing her long hair and feminine appearance.
* ''LightNovel/KinosJourney'': [[AmbiguousGender Kino]] is a girl. The anime doesn't tell you until the fourth episode and you don't find out for quite a while in the non-English novels, before which most viewers tend to either assume she's a boy or think "But he could be...". The people who figured it out before hand got to give themselves a good pat on the back when her gender was finally revealed.]] Strangely, it is Japan in which this is easy to guess due to seemingly CrossdressingVoices, the English dub gives the character a much more ambiguous voice. Though it's not uncommon in anime for adolescent males to have distinctly effeminate voice.
* ''Lightnovel/FullMetalPanic'': In the Second Raid, Mithril agent Wraith is revealed to be a woman. She disguised herself as an overweight man complete with a voice changer.
* With Hinagiku taking the role of Silver Red (a superhero of a Sentai parody), ''Manga/HayateTheCombatButler'' is setting itself up for this one. The other characters even think Red ''is'' a guy, despite the significant lack of male form ([[ACupAngst not just Hina's]] UsefulNotes/{{Pettanko}} status).
* In ''Anime/KirbyRightBackAtYa'', Princess Rona initially introduces herself as the MALE bodyguard Vee to the decoy princess because she wanted to get to know the people of Cappytown as a normal person. It's not until her helmet falls off later on that any real girlishness is revealed. She still manages to kick Dedede's ass at the end in a swordfight even after being revealed as the actual princess. Though in this case, the deception was intentional, not just that wearing that particular suit or whatever was the most logical thing to do for an action hero.
* Busujima from ''Manga/BusouRenkin''.
* A 1987 anime version of ''Anime/TheThreeMusketeers'' does this to [[GenderFlip Aramis]].
* In ''Manga/DeathNote'', Misa Amane is revealed to the readers to be the second Kira soon after her activities become known to the other characters. In the English versions at least, Light and the investigators continue to refer to The Second Kira by the male pronoun (probably for the sake of convenience, as they use "he" when referring to the first Kira too) until they learn more about her.
* Played with in ''Anime/SpacePirateMito''. During a fight, BigBad Ranban's helmet is knocked off, revealing not only a female face underneath, but the same face as Aoi's mother, the titular Mito. Ranban reveals that it's just a [[PoweredArmor mail suit]], which Mito also wears, modeled on the first queen of the galaxy. Later on, however, it's revealed that Ranban never differentiated between genders, as his species usually does at puberty, and is thus a {{hermaphrodite}}.
* In ''Manga/OnePiece'' Movie 4, the little kid whom Luffy and Co. encountered was revealed to be a girl dressed in boy's clothing near the end.
* Sevotharte from ''Manga/AngelSanctuary''. The promising scientist Lailah's success elicited jealousy from her male peers, who [[RapeAsDrama raped her]]. Branded a Fallen Angel for becoming "tainted," she sold herself in desperation to [[FetusTerrible Sandalphon]], who whitened her hair and altered her face and body type. Since the true Sevothtarte died years ago in combat, she took his name and wore a tiara and veil to hide her identity after she ascended into the Seraph rank.
* ''Manga/{{Naruto}}'':
** Used during the Land of Birds filler arc. An armored, flying specter wielding a naginata appeared to haunt a daimyo's castle which had recently seen great misfortune; the specter seemed intent on uncovering if an assassin had slain the former daimyo and his daughter. It was eventually revealed that the specter was [[spoiler: Toki, the supposedly deceased daughter; after her twin brother Sagi and their father were poisoned, she disguised herself as Sagi in order to assume the lordship and discover the killer's identity]].
** Subverted much earlier during the Land of Waves of arc. Haku's first appearance showed [[DudeLooksLikeALady her]] to be highly-skilled and convinced even Kakashi that [[WholesomeCrossdresser she]] was a threat while wearing bulky robes that could disguise a feminine form. A chance meeting with Naruto while in civvies set up the possibility of a forbidden romance... and then Haku had an UnsettlingGenderReveal.
* In ''LightNovel/{{Durarara}}'', Celty's gender isn't clear when she first appears thanks to camera angles and lighting, although her feminine form is much more apparent later on. It's apparently less obvious in-universe than it is to the viewers; neither Shizuo nor Tom knew that Celty was female until Shinra told them.
* Melk the Second from Toriko starts off appearing to be a very [[{{Bishonen}} bishie man]].
* ''Manga/IceRevolution'': Most of Masaka's friends at the skating rink thought she was a boy... until she took the ice for her first performance. Heck, her own coach didn't even notice she was a girl until she told him.
* Kei in ''Anime/IriaZeiramTheAnimation''. She's pre-adolescent, so there's no way to distinguish that she's a girl dressed in boy's clothes until late in the series when Fujikuro literally sniffed out her gender.
* ''Manga/BlueExorcist'': In episode 12 Yamada, who always wore a hood and never spoke, turns out to be Stripperific ActionGirl named Shura, wearing a disguise to spy on our main characters.
** In the 20th anime episode, the villain working with Neuhaus turns out to be his wife, despite having used a distinctly male voice up until TheReveal.
* The titular character in Creator/OsamuTezuka's ''{{Dororo}}''. It doesn't help that she was told she was boy by her parents.
* In ''Manga/SgtFrog'', many characters first think that Private Tamama is a female due to his cute appearance and voice. Later on in the series, Tamama himself, along with most of the rest of the cast, falls victim to this trope when a Keronian named Karara comes to Earth to see the Keroro Platoon (known as the "ARMPIT" Platoon in Funimation's dub [[note]]which is either a {{Woolseyism}}, a GagDub, or a {{Macekre}} depending on who's asked[[/note]]). It's not made apparent that she's female until she leaves a goodbye note when she leaves at the end of the episode, saying that Tamama left such a huge impression on her that she wants to marry him when she grows up. In all the character's defense, an actual female Keronian hadn't shown up before then.
* Brilliantly pulled in ''Anime/InfiniteStratos''. Ichika accomplishes the impossible and moves an IS, something that's said to be impossible to be done by males. He gets himself enrolled in an all-girl school... then after a while, another male by the name of [[{{Bishonen}} Charles Dunois]] is transferred into the class and said to have accomplished the same feat. He is awfully shy around Ichika in the locker room and [[spoiler:refuses to change with him, something Ichika finds quite strange and tries to lightheartedly force the issue, only to provoke the other boy into running away. When he returns to their mutual room, [[ShowerOfAwkward Dunois is in the shower and Ichika enters the bathroom just as the former was about to leave the cubicle]].]] Yup, [[SweetPollyOliver Dunois]] is [[FullFrontalAssault definitely not a guy]]. "He" later explains that [[spoiler:as an illegitimate child, she was kept in secrecy until a few years ago when she was tested and found to have a good aptitude at using an IS. Her [[WholesomeCrossdresser disguise]] as a boy served two reasons: first, as a publicity stunt to her father's company which was falling behind in IS development and second, as a way to [[TheMole get close to Ichika and spy on him]].]] A few days later, Ichika's class receives another transfer student. Everyone, say hello to [[{{Moe}} Charlotte Dunois]]. Naturally, everyone in the class knows Charlotte and Ichika used the bathhouse together the previous night and instantly make the assumption he must've known and [[AccidentalPervert took advantage of it]]. Cue [[{{Yandere}} Rin]] [[PervertRevengeMode bursting into the classroom with her IS and firing a full-powered shot at Ichika's head]].
** And as a little extra, Charles/Charlotte also happens to be a CharClone and later becomes a LoveInterest for Ichika.
*** And as a little extra extra, her nickname, given to her by Ichika, IS Char. Go figure.
* ''Manga/FushigiYuugi'' has Soi, who was a person wearing a cloak for a few chapters before revealing herself as a woman.
* A villainous example appeared in ''Anime/BrainPowerd'' -- the enigmatic Baron who begins to appear late in the show is quite fearsome, helping the villain Jonathan transform his [[HumongousMecha Grand]] [[EmpathicWeapon Cher]] into a borderline EldritchAbomination known as the "Baronz." His reasons seem mysterious and ChessMaster-y, but... [[spoiler: behind the mask, it's actually Jonathan's estranged mother, trying to protect and help her son despite being stuck on the wrong side of the conflict from him.]]
* Inverted in ''LightNovel/{{Baccano}}'', where Claire Stanfield, the expert assassin named Luck had hired, turns out not to be the [[RedHerring fatigues-wearing]] ActionSurvivor woman [[RedHerring that'd been making her way across the train]], but rather [[spoiler:[[RedHerringShirt the redheaded conductor that was supposedly killed off very early on in the story.]]]]
* The acolytes in ''Anime/AgnisPhilosophy'' are all presented to the viewer as robed, hooded individuals, so the viewer can be forgiven for [[MenAreGenericWomenAreSpecial assuming they are male]] until the titular character pulls off her hood, revealing that "he" is, in fact, a she.
* In ''LightNovel/ACertainMagicalIndex'', the villainous organization GREMLIN, which is mostly made up of people with Myth/NorseMythology gimmicks, is led by someone called Odin. Surprise, [[spoiler: Odin is Othinus, who ''looks'' like a 13-14 year old girl and is still powerful enough to CurbStompBattle pretty much anyone since she indeed has the power of the Norse God Odin.]]
* In ''LightNovel/MaoyuuMaouYuusha'', [[NoNameGiven The Hero]] was greatly surprised to find that The Demon King is [[SheIsTheKing a really cute girl]].
* In the original series plan for ''Anime/ScienceNinjaTeamGatchaman'', Berg Katse would have turned out to be a woman disguised as a man. About halfway through, the producers changed their minds...
* ''Anime/IrresponsibleCaptainTylor''. Harumi takes off her helmet and baggy spacesuit to reveal she's a HospitalHottie, causing Dr. Kitaguchi to lose a SideBet that their latest crewmember would not be a woman.
* ''Anime/LupinIIIPrincessOfTheBreeze'' has Lupin fighting a Sky Pirate in a bird-beak mask. When Lupin pushes on the pirate's chest to keep them away from him, the pirate is upset. It turns out ''she'' is a young girl. Cue weaponized ArmorPiercingSlap, and Lupin getting knocked off of the airship.
* In the ''Anime/{{Gaiking}}'' CGI test footage, the pilot was revealed to be a woman. In its previous incarnations, Gaiking's pilots were both male.
* ''LightNovel/{{Shimoneta}}'' inverts it with Oboro, who [[AloofDarkhairedGirl looks]] ''[[CrossdressingVoices and sounds]]'' so feminine, that no one realizes he's actually [[DudeLooksLikeALady a male.]] At least, not until the locker-room scene [[CrotchGrabSexCheck between him and Tanukichi]] in episode 9. When Tanukichi tries to tell Ayame about it, she finds it so hard to believe that she [[CassandraTruth dismisses it]] as a weak excuse for his failure to catch the underwear thieves.
* ''Manga/TokyoGhoul'' and its SpinOff[=s=] use this trope.
** In the main series, the [[TheDreaded legendary]] [[HalfHumanHybrid One-Eyed]] [[BigBad Owl]] is revealed to be a young woman. The loose cloak and massive [[InstantArmor Kakuja]] armor she wears completely concealed her form, making it easy for her own father to impersonate her more than once. In a further twist, it turns out that she's ''also'' the mysterious and greatly-feared "One-Eyed King", the leader of [[TheSyndicate Aogiri]]. People just ''assume'' the King is a man, which she uses to be a KingIncognito.
** Lantern, the SerialKiller Ghoul from the {{Prequel}} ''Jack''. Wearing a Jack-o-lantern mask and a large trench coat, she takes full advantage of people assuming that Lantern is a man.
** The leader of the Skull Gang in the ''Joker'' One-Shot. Known as a deadly and vicious Ghoul terrorizing the 13th Ward, the fact that she turns out to be a pretty teenage girl takes Hanbee completely by surprise.
* ''Manga/DetectiveConan'':
** Natsuki Koshimizu is a quiet and short-haired young woman, who is believed by some of her fellow {{amateur Sleuth}}s (and the audience) to be a boy. Then [[GenderReveal she shows up]] [[SheCleansUpNicely wearing a]] SailorFuku...
-->'''Conan''': "... So he is a she?!"
** This trope makes a return with the character Masumi Sera. In her first appearance she at first appeared to be a rival love interest for Ran's affection, with the cast only discovering she's a woman when she starts school. This becomes a recurring theme, with characters constantly mistaking her for a male on their first meeting [[spoiler:including Kaito Kid, [[MuggedForDisguise who tapes her up and disguises himself as her]]]]. This leads to a rather comedic scene at the end of the case when Conan reveals this [[spoiler:just in time for Sera to break free and re-enter in her underwear]]. To be fair though, she ''did'' use her masculine appearance to get into the men's restroom because there was a large line for the women's, so the confusion is understandable.
* In the second season of ''LightNovel/SwordArtOnline'', Yuuki's [[note]]known at this point as [[RedBaron Zekken]][[/note]] badassery is established when she defeats [[InvincibleHero Kirito]] in a duel. The only reason the audience doesn't know she's a girl, however, is because the duel takes place offscreen, and we only see it as a combination of :[[TheBlacksmith Liz]] relating the story to [[LadyOfWar Asuna]], who wasn't present at the fight, the fact that Liz forgot to mention her gender, and Asuna's imagining of the scene (presented as a kind of pseudo-flashback), where she pictures Zekken to be some badass dude in bulky black armor. Hilariously, upon finding out, Asuna suspects Kirito lost because the reveal distracted him, but in a later montage, it shows that she ''still'' defeats him, mainly because of [[spoiler:her AIDS]], which for the past three years has forced her to live full time in the virtual world [[spoiler:while her real body undergoes treatment]]. As a result, she has a whole year more virtual life than Kirito, and he went so far as to say that if she was in SAO, ''she'' would have gotten the DualWielding skill, not him.
** In ''Progressive'', Liten is introduced as a heavily armored "tank" player with a helmet that conceals the face, and is initially not referred to with gender-specific pronouns in the illustrated page introducing Kirito and Asuna's party for taking on the boss of the fifth floor. Much to Kirito's surprise, Liten is revealed to be a girl after she takes off her helmet.
* During the Neo TV arc in ''Manga/TriageX'', the terrorist leader Wild Hunt is later revealed to be a woman named Siren who can change her voice by manipulating her throat.
* ''Manga/YuushaGojoKumiaiKouryuugataKeijiban'' takes place on an interdimensional message board for "heroes" of all types, with new users given the generic handle "Hero." Many chapters feature a hero whose gender isn't revealed for several pages, including a Japanese schoolgirl summoned into another world and saddled with a divided party, Wandering Sword who wants to get closer to catgirls, and a knight burdened with a womanizing holy sword that transforms into a handsome man.
* In ''Manga/{{Eyeshield 21}}'' there's Karin Koizumi, the quarterback of the Teikoku Alexanders. What makes her remarkable is that not only is she a female playing American Football, she's the quarterback of Japan's ''best high school football team''.
* ''LightNovel/{{Campione}}'':
** Lancelot of the Lake used magic to have a deep voice and appear to be a man when she has her armor and helmet on.
** Annie Carlton took on the masked and costumed persona of John Pluto Smith.
* For most of ''Manga/DeadmanWonderland'' Ganta assumes that the "[[InSeriesNickname Red Man]]" who killed his classmates was a man. She's not. [[spoiler:In fact, she is Shiro, his close ForgottenChildhoodFriend and a teenage girl at that.]]
* In ''Manga/MyHeroAcademia'', the seventh wielder of One for All and the master of All Might was only known as "Shimura" for a while. About 40 chapters later, her full name was revealed as "Shimura [[SevenIsNana Nana]]," then the next chapter features her in a flashback, confirming her gender as a woman.
* In the manga adaptation of ''VideoGame/MegaMan6'', Centaur Man is revealed to actually be a woman who disguises as a male and has a crush on Knightman. It doesn't carry over into any other adaptations, but many fans will still argue that it's canon.
* Non-human example in ''Anime/{{Beyblade}}''. Despite what the dub says, most of the Bit-Beasts [[AmbiguousGender have no known gender]]. Tala's Wolborg fell under this category until his battle with Kenny during ''G-Revolution''. When Tala [[SignatureMove employs his]] [[AnIcePerson Novae Rog]] [[FinishingMove to end the match]], [[https://www.youtube.com/watch?v=wSyFFbz61fo#t=36s a beautiful ice maiden is briefly shown]] right before Kenny's Beyblade is frozen solid by Wolborg. While it's easy to attribute the inexplicable appearance of this figure to RuleOfCool, this being the only time in the series Novae Rog uses that particular animation sequence, the mysterious woman actually ''[[HumanityEnsues is]]'' Wolborg. The lone hint is the tiara worn by the ice maiden, [[MorphicResonance which resembles the small crown on Wolborg's head]].
* In ''Manga/SakuraTrick'', the person Kotone is betrothed to is revealed to be a woman named Sora.
* The John Titor character in ''Anime/SteinsGate'' is actually [[spoiler: Suzuha Amane]]. The anime even uses male voice actor in John Titor's email conversations with protagonist Okabe before the eventual [[TheReveal reveal]].
* In ''Manga/AttackOnTitan'', the Titan Shifter with the ability to become the Cart Titan turns out to be a young woman, even though unlike the Female Titan, the Cart Titan is not apparently feminine.

[[folder:Comic Books]]
* One of the regular supporting heroes in Paul Grist's ''ComicBook/JackStaff'' is Tom Tom the Robot Man, a towering, super-strong robot with the power of flight. It's a genuinely bizarre and unexpected moment when it's discovered that "he" is effectively a suit of powered armour being piloted by a disabled girl genius to fight crime.
* In the one-shot crossover ''Comicbook/SpiderMan vs. ComicBook/{{Wolverine}}'', both heroes are on the trail of Wolverine's former partner, named "Charlie", which is given as being short for: "Charlemagne". When Wolverine finally catches up with Charlie, the rogue agent is revealed to be a "she". Wolverine naturally knew all along, but Spidey, as well as the READER were kept in the dark by clever avoidance of gender-specific pronouns (not to mention a flashback where "Charlie" is deliberately shown in gender-neutral disguise). It's implied that Charlemagne uses the ambiguous nature of her name as an additional cover to her identity.
* In ''Comicbook/XMen'', Professor X's primary love interest Lilandra is introduced in a running subplot in which he is having ominous visions of space battles and a menacing armored figure. When the figure finally shows up and takes off its helmet, it isn't quite what he is expecting.
* The original Ronin in ''Comicbook/NewAvengers'' turned out to be Comicbook/{{Daredevil}}'s love interest Echo (after a minor RedHerring that it was DD himself).
* Julie-Su from the ''Comicbook/SonicTheHedgehog'' comic.
* An early arc of ''Comicbook/{{Wolverine}}'s comic involved an up-an-coming crime boss in Madripoor called Tyger-Tiger challenging Roche's hold on the nation's underworld. Roche had no idea who Tyger-Tiger was, and in one part, believed it was a male rival. In truth, Tyger-Tiger was [[DarkActionGirl Jessan Hoan]], and as a result, her final assault on him came as complete surprise.
* ''Comicbook/{{Empowered}}''
** [[spoiler:Mindf**k]] is a dramatic example, as eventually revealed to Emp; [[spoiler:Mindf**k]] and [[spoiler:Sistah Spooky]] are ex-lovers, whose first meeting (without a Samus Is A Girl scene) was shown in flashback the following volume.
** The supervillain [[spoiler:Deathmonger]] was eventually revealed to be a woman under her mask.
* [[spoiler:Junior, who is assumed to be Ragdoll's brother or father]] in ''Comicbook/SecretSix'', turns out to be his [[spoiler:sister]].
* Sasquatch from ''ComicBook/AlphaFlight'' is ''usually'' male in the main continuity, but in the [[ComicBook/UltimateMarvel Ultimate Universe]], when the team returns to base after fighting the X-Men, Sasquatch resumes human form and turns out to be the very female Rahne Sinclair, who in the main MarvelUniverse is the werewolf Wolfsbane. There were some hints to this beforehand though; readers may have wondered why "he" had [[TertiarySexualCharacteristics ribbons]] in "his" hair in Sasquatch form.
** Sasquatch from ''The Exiles'' as well. First going into human form: "What surprises you more, that I'm a woman or that I'm black?"
** This happened even in the main continuity. When Sasquatch came back from the dead by using the body of the shapeshifting Snowbird, he first appeared in his Sasquatch form but, when he tries to resume his human form, he discovers that he's trapped in a feminine body, since Snowbird was a woman.
* Shining Knight, from Creator/GrantMorrison's ''[[ComicBook/SevenSoldiers Seven Soldiers of Victory]]'', is revealed to be a girl at the end of her portion of the series.
** Ystin being female is taken as a given when she appears in Demon Knights, though most people are polite enough not to point this out.
* Colonel Randall in Dark Horse's early ''Franchise/{{Terminator}}'' comics is introduced as a gritty soldier in combat fatigues and a face-obscuring helmet, and only referred to as 'the Colonel'. This is really only to build up to the money shot, where, after having stripped down to go through Skynet's time machine, Colonel ''Mary'' Randall blows away a terminator and is shown to be... a hot nekkid babe! Needless to say, on arriving in the 20th century she starts wearing tight minidresses.
* In ''ComicBook/TheSandman'', Death's name is mentioned well before we see her. Gaiman intended for most readers to assume Death of the Endless would be male and menacing ... until we saw her.
** [[{{Squick}} In-character example]] from the same series: [[spoiler: "[[SerialKiller Dog Soup]] is a ''woman''?"]]
* ''ComicBook/TheSurrogates'' features a setting where normal people no longer interact with each other in person, but instead use a [[UnusualUserInterface humanoid robot]] as a proxy. As a result, cross-gender surrogates are common. One of the first surrogates we see is a cross-gender surrogate, and the male CorruptCorporateExecutive is revealed to actually be a woman. Both of them masqueraded as a person of the opposite gender to get ahead in their respective fields.
* In ''ComicBook/{{Camelot 3000}}'', Merlin sends Tom to a wedding to awaken the memories of a reincarnated Round Table knight. The homing-amulet he's carrying leads him to the couple at the altar. Tom assumes it's the groom he's looking for, but it's [[GenderBender actually the bride]] whom Sir Tristan has been reborn as. Of course, the now awoken Tristan fully identifies as a man and draws a great deal of angst from it.
-->'''Tristan:''' My name is Tristan. '''Sir''' Tristan.
* Taz in the ''ComicBook/AtariForce'' second series was referred to as being male up until Morphea discovered [[spoiler:Taz not only was actually female, she was [[PregnantBadass pregnant]]]].
* In ''ComicBook/ScudTheDisposableAssassin'', Sussudio is introduced this way. [[spoiler:Naturally, she later becomes Scud's love interest.]]
* In DC's 1980s comics series ''ArakSonOfThunder'', the character of Valda is introduced in full plate armor. Arak doesn't find out her sex until he removes her helmet. Unfortunately, the cover spoils the surprise by showing her wearing her standard mail byrnie and no helmet.
* "The Trouble With Air", the cover story of an issue of DC's horror anthology series ''Unexpected'', has an astronaut saved from a lonely death on Pluto by the, well, ''unexpected'' action of some friendly native blobs. In the very last panel, after returning to the lander, the astronaut removes their helmet - allowing ''her'' curly hair to fall to the shoulders of her spacesuit.
* Johnathan Hickman's ''[[Comicbook/TheAvengers Avengers]]'' run introduced Comicbook/IronMan 3030, a futuristic LegacyCharacter. The bulk of the character's debut issue deliberately leaves their gender ambiguous, only for the final few pages to reveal that Iron Man 3030 is actually Tony Stark's [[AffirmativeActionLegacy mixed-race granddaughter]], Rhodey.
* The Belgian comic ''ComicBook/LamentOfTheLostMoors'' takes this even further with the [[http://lelitoulalu.blogs.lindependant.com/media/00/01/1044022232.jpg Guinea Lord]], a terrifyingly badass BlackKnight, by making him (well, her) the crippled daughter of a powerful sorceress, the armor itself giving hellish strength and endurance to the wearer.
* The [[CopKiller Hangman]] from the Franchise/{{Batman}} miniseries, ''ComicBook/DarkVictory'' turned out to be [[TheDon Carmine Falcone]]'s daughter, Sofia Falcone, ObfuscatingDisability and seeking revenge against Two-Face and everyone who helped pre-Two-Face Harvey Dent's rise as District Attorney (as Dent's first act as Two-Face is to kill her father).
* ''[[Comicbook/TheAvengers The Avengers]]'' #145 (from 1976) introduces a hired killer known only as [[ExactlyWhatItSaysOnTheTin The Assassin]], who wears a bulky armored costume with a full hood. In issue #146, the Assassin's hood gets knocked off to reveal that she's a woman. She then proceeds to lecture Hawkeye for being surprised by her gender, considering the number of [[ActionGirl Action Girls]] on his own team.
* The nameless rope-walker in Brandoli and Queirolo's ''Alias''. Nobody catches on until she comes on to the hero at the very end.
* In ''ComicBook/TheHaloGraphicNovel'' story ''Armor Testing'', Spartan-II Maria-062 isn't revealed to be female until the very end, after she takes off her helmet and her commanding officer finally refers to her by name.
* ''ComicBook/WhateverHappenedToTheCapedCrusader''. In Selina Kyle's story of how she first met Batman, she's wearing a [[CheapCostume fullface cat mask and flowing cape]] instead of the familiar slinky catsuit. So Batman gets a surprise when her mask comes off during their struggle.
-->'''Batman:''' But you're...[[FoeRomanceSubtext beautif--]] ''(gets slashed by FemmeFatalons)'' OW!
* ''Manhwa/WitchHunter'' pulls this card with [[spoiler: Halloween, Tasha's pumpkin-headed marionette]] who is initially thought to be genderless due to [[spoiler: being a marionette]] and all that, but when [[spoiler: Tasha]] breaks [[spoiler: Halloween]]'s first seal, its true form is revealed to be [[http://download.minitokyo.net/Witch.Hunter.477596.jpg this.]] Tasha is, naturally, shocked.
* The 1953 EC Comics story "Judgment Day", although [[spoiler: the example is racial rather than sexual]]. The planet the story takes place on is populated by orange and blue robots. They are identical but for outer casings and programming, but the blue robots sit at the back of the bus, recharge in different stations, live in their own sector in town. The human evaluating the robot society does not let them progress to space until they can get over that, noting that Earth was like this once, and only owned the universe after humans learned to live together. In the last panel of the story [[spoiler: he takes off his helmet, revealing that he is black]].
* ''ComicBook/{{Thunderstrike}}'': Eric battles the villain Bloodaxe, and then finds out it's really his girlfriend, Jackie.

[[folder:Comic Strips]]
* In ''ComicStrip/FunkyWinkerbean'', The Eliminator was a EnfantTerrible arcade gamer of such skill, he could make a Defender machine tilt like a pinball game. His face was always covered by a visored helmet (a ShoutOut to Darth Vader, as ''Film/TheEmpireStrikesBack'' was THE hot movie at the time of his debut). Midway through the first TimeSkip, the grown-up Eliminator was reintroduced... as Donna, a hot blond woman. She eventually ended up dating and marrying Crazy Harry, who'd considered The Eliminator his nemesis back in high school.
* In ''ComicStrip/MotherGooseAndGrimm'', Grimm was shocked to learn that his hero, the star of the TV show ''Karl the Wonder Poodle'', was a female poodle named Karla.
* ''ComicStrip/BloomCounty'' had a whole arc devoted to this. It started when Budweiser mascot Spuds [=MacKenzie=] visited Opus and told him that most animals who appeared in the media who were "billed" as male were actually females - including Spuds. He - or rather she - then claimed this was also true for one of the animal characters in ''Bloom County'', but then fell into a drunken slumber, which Opus predicted she wouldn't wake up from until "that last comment has caused total pandemonium around here". Indeed, the animal characters launched their own investigations (Portnoy quickly finding out that "cartoon characters aren't anatomically correct") even going so far as to use a JackBauerInterrogationTechnique on Bill the Cat, until Opus finally discovered it was Rosebud the Bassalope. From that point on, she was referred to by her true gender.

[[folder:Fan Works]]
* ''Fanfic/ACrownOfStars'': In a late chapter Shinji, Asuka and the rest of the cast seize an enemy fleet. Misato was wearing a PoweredArmor during the battle, and the admiral of the fleet got shocked when she removed her helmet’s faceplate and revealed that she was a woman:
-->''He blinked in surprise to see the smiling woman revealed by the now transparent helmet.''
* ''Fanfic/BatmanBeyondRevisited'': Poetic license at its finest; not only does [[spoiler:Payback]] turn out to be a girl, she’s also [[spoiler:Jake’s mother.]]
* Saved for the end and {{exaggerated}} in "Fanfic/{{Frostbite}}", with the entire rest of the fic having used male pronouns for Breen [[TheCaptain Dalsh]] Ruul. When Dul'krah removes Ruul's helmet, it turns out she's not only female, but ''human''.
* In the ''ComicBook/JudgeDredd'' short fan film ''Film/JudgeMinty'', Minty kills a masked gang member in the Cursed Earth, only to find out to his dismay that it was a girl of about 20.
* Happens in the ''Fanfic/PonyPOVSeries'' during the Wedding Arc when a trio of guards that helped [[HeroOfAnotherStory Misfit Actual]] named Weaver, Diver, and Bombardier are revealed to be Changelings. As it turns out, Bombardier is a female Changeling assuming a male form because of Changeling BlueAndOrangeMorality. Changelings simply have a different concept of sex and gender than ponies and she simply preferred having a male alternate form. She mentions this made finding a lover a bit difficult.
* ''Fanfic/TheEquestrianWindMage'': Fluttershy reveals that Volvagia the lava dragon is female, much to Vaati's shock.
* ''Fanfic/FairyWithoutWings'': [[EveryoneCallsHimBarkeep Dark Blade]] the Knight of Seven of the Edolas Knights of the Round is a true and tried BlackKnight and the epitome of DarkIsEvil. Claims that the person they are is dead inside and only so many people know this swordsman's identity. Totally, Edolas Lelouch, right? [[spoiler:[[{{Fauxshadowing}} Wrong!]] [[WhamEpisode It's Nunnally]]]]
* In [[https://archiveofourown.org/works/4034221 ''Meeting Someone New'']], a ''Film/TheHobbit'' fanfic on Website/ArchiveOfOurOwn, new settlers come to Erebor, and Kíli hates one of them, a brave warrior, at first sight, because he's everything Kíli is not. When the stranger starts to court Kíli, hate turns to love. When the other dwarf reveals that she is a woman, Kíli is surprised, but not shocked. As all dwarves have beards, no helmet is required for the misunderstanding to happen.
* In ''Fanfic/AshesOfThePast'', Ash's Pidgeot turns out to be female [[BerserkButton and does not like being mistaken for male.]]
* In Franchise/{{Metroid}}/''Literature/{{Worm}}'' roleplay quest [[http://forums.sufficientvelocity.com/threads/hatchling-quest-worm-metroid.22540/ Hatchling Quest]], PRT's Head of Image brings this up when [[http://forums.sufficientvelocity.com/threads/hatchling-quest-worm-metroid.22540/page-19 he remarks that Samus could easily pass for a boy while wearing her Power Armor]]. This trope (befittingly) becomes something of a RunningGag throughout the story. Samus keeps a SecretIdentity, and even though it's been publicly stated she is a girl from another universe, there are people who think she's a boy (or a robot). Even those who accept the official explanation are still surprised to find there's a blond girl under the power armor.
* In ''Fanfic/{{Wonderful}}'', no one knew that [[TheHero Wonder Red]] was a girl until she revealed herself.
* In the ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' fanfic ''Beware the Equalizer'', the titular character wearing PoweredArmor and a CoolHelmet and wielding a MagicStaff is revealed to be none other than [[spoiler:[[StepfordSmiler Starlight Glimmer]]]].
* In ''WesternAnimation/ThePowerpuffGirls'' fanfic ''Fanfic/{{Ladder}}'', the SerialKiller known as "the Harvester" is out killing criminals. She's referred to as male however eventually she is revealed to be female. She is [[spoiler:Bubbles]].
* Part of ''[[Creator/DetsniyOffSkiword Profesor Layton Vs Jack The Raper]]'''s big reveal is that Jack The Raper is a female.
* Averted [[spoiler:and later invoked]] in ''[[https://www.fanfiction.net/s/11772125/1/Metroid-Kamen-Rider-Generations-Full-Series Metroid: Kamen Rider Generations]]''. After subsequent encounters with different Riders, most Franchise/KamenRider characters are fully aware of Samus's existence.
* In ''Fanfic/TheElementsOfFriendship'', both Celestia's bodyguard Paper Mache and Pinkie's sister Maud are mistaken for stallions when first introduced.
* In chapter 2 of ''[[https://www.fanfiction.net/s/12213237/1/Metroid-Kamen-Rider-Generations-Vol-2-Ex-Aid-Era-feat-Cross-Ange Metroid: Kamen Rider Generations Vol. 2 -- Ex-Aid Era feat. Cross Ange]]'', the second season to the aforementioned ''Metroid: Kamen Rider Generations''; [[Anime/CrossAnge Ange]] learns the hard way that Samus and the mysterious armored man who saved Tusk and Momoka are actually one and the same person. The fact after Samus sheds her armor in front of Ange, Tusk, and Momoka left them utterly speechless.
* In ''FanFic/RobbReturns'', a short lived version appears when the man Brynden Tully meets on his way south ends up revealing himself as Brienne of Tarth a few moments later.
* ''Fanfic/PokemonResetBloodlines'': Ash has this reaction with his Pidgeotto, and later with Roggenrola. The latter was a notable case given that he was certain of the gender of all of his Unovan mons.

[[folder:Films -- Animation]]
* In ''WesternAnimation/BatmanMaskOfThePhantasm,'' [[spoiler:the Phantasm]].
* From ''Anime/FinalFantasyTheSpiritsWithin'', before the soldiers take off their helmets:
-->Hear that, Jane? [[ShoutOut She thinks]] [[Film/{{Aliens}} you're a man]].\\
I think she's an idiot.
* ''WesternAnimation/HeavyMetal'': The title character of the last story, Taarna, is summoned by the city's elders to fight the horde of evil invaders. The elders don't use any gender-specific words when speaking of the last of the Taarakians whom they're summoning, and when Taarna does arrive, she flies into the city on a pterodactyl-like steed wearing a hooded robe. Only when she lands in the city and dismounts her steed does Taarna reveal her gender by removing her hood (and shortly thereafter, [[FanService everything else]] to keep up the film's quota).
* Technically, the stitchpunks of ''WesternAnimation/{{Nine}}'' are asexual constructs. This trope is still invoked with 7, whose female voice isn't heard until after "she" has demonstrated "her" combat prowess.
* Goblin minion Stuff in ''WesternAnimation/StrangeMagic'' thought it was obvious that she was female. Her male coworker might just be that dumb.
* One of the main villains of ''WesternAnimation/TheCondor'', Taipan, is revealed to be Tony's girlfriend Valeria who wanted to have "''some fun''" with him before she kills him. Helped by the voice distorter and masculine nature of her costume.
* Valka in ''WesternAnimation/HowToTrainYourDragon2''. Even though {{Action Girl}}s are perfectly common and accepted in the film's culture, the mask and armor conceal the figure's shape and size completely, making it a surprise when it turns out to be a woman, helped by the fact that Hiccup and the viewer have been given reason to suspect it was the man Drago he's just heard about.
* In ''WesternAnimation/KuboAndTheTwoStrings'', Kubo's mother uses the last of her magic to bring to life his wooden monkey charm. Kubo had though of the charm as male, but Monkey turns out to be female [[spoiler:due to being inhabited by his mother's soul]].
-->'''Kubo:''' I called that charm ''Mr.'' Monkey.
-->'''Monkey:''' And if I were alive at that point I might've found that insulting.
* In ''WesternAnimation/TheFlightOfDragons'', the [[RagtagBunchOfMisfits band of heroes]] is saved from a pack of thieves by a Robin Hood wannabe. When the knight in the group goes to thank the mysterious archer, "he" takes off "his" cap, and the audience is treated to a slow-motion shot of long, glistening red hair as it flows down below her waist. The knight is speechless.
* One of the main villains of ''WesternAnimation/TheCondor'', Taipan, is revealed to be Tony's girlfriend Valeria who wanted to have "''some fun''" with him before she kills him. Helped by the voice distorter and masculine nature of her costume.

[[folder:Films -- Live-Action]]
* Demetra, from ''[[Film/SpyKids Spy Kids 3D: Game Over]]'', wore a head-obscuring helmet during her stay with the gang that Juni joins. RomanceArc? Check.
* Maid Marian's initial appearance in ''Film/RobinHoodPrinceOfThieves'', followed shortly after by {{Chickification}}.
* From ''Film/SkyHigh2005'', power-armoured supervillain Royal Pain turned out to be [[spoiler:Gwen, the girl that Will had a crush on. The weapon she built before being defeated by Will's superhero parents turned her into a baby, and her henchman raised her.]]
* In ''Franchise/StarWars'':
** [[Film/ReturnOfTheJedi Boushh]] is [[spoiler:Leia]] disguised as a bounty hunter with a voice-altering mask.
** Rumored to have been the case for Boba Fett for a while, which would have put quite a different spin on the scene at Jabba's palace, where Boba makes a pass at one of the dancer girls. It's hinted at in a young reader book, and in fact his appearance in that book was later retconned to have been his daughter impersonating him.
** Captain Phasma in ''Film/TheForceAwakens'' wears the standard Stormtrooper armor, albeit a more decorative one indicating rank, but then speaks in a clearly female voice. In addition to her, one of the regular Stormtroopers also clearly has a female voice, implying female soldiers are a normal thing among the First Order (and possibly [[{{Retcon}} were in the Empire]]).
** From the same film, Rey is initially introduced wearing loose clothing and headgear that make it difficult to tell that she's female.
** In the anthology film ''Film/{{Solo}}'' it's revealed that [[spoiler:Enfys Nest]], who wears gender-obscuring armor and uses a voice filter, is a very young woman allied with the nascent Rebellion.
* This seemed to be the idea behind Nyssa's first scene in ''Film/BladeII''. It didn't quite work. In fact, it would probably count as a genuinely surprising subversion of this trope if an armored antagonist were to wordlessly, facelessly appear, go toe-to-toe with the male protagonist using acrobatic moves, and then be revealed to ''not'' be female.
* ''[[http://www.imdb.com/title/tt0082622/ Knightriders]]'', Sir Rocky.
* ''Film/{{Thunderball}}''. A motorcyclist kills a man driving a car (who's chasing Film/JamesBond) and rides away. After running the cycle into a ditch, the cyclist takes off the helmet and reveals that she's SPECTRE assassin Fiona Volpe.
* In ''Film/{{Dragonslayer}}'' (1981) a character turns out to be [[spoiler:a girl masquerading as a boy since girls are in danger of being sacrificed to the dragon.]]
* ''Film/{{Hackers}}'': Neither Dade nor the audience know that Dade's rival, Acid Burn, is actually his love interest, Kate Libby, until a hacker lets that information slip about halfway through the film. Dade's fellow hackers do know who Acid Burn is, but when Dade initially assumes Acid Burn is male--"Do you know who he is?"--they gladly let him go right on thinking that--"No, I don't know who he is".
** From Lord Nikon's point of view, this is the case with Zero Cool, Dade's hacker alias when he was a kid (and responsible for one of the worst cyber-attacks in history). Being black, Nikon naturally assumed so was Dade.
* Film/{{Barbarella}} in the beginning of the original film, where a bulky spacesuit is removed, and FanService ensues.
* Trinity in ''Film/TheMatrix'', from Neo's point of view; he'd heard of Trinity in Cyberspace [[ThereAreNoGirlsOnTheInternet but assumed it to be a guy.]] Trinity replies that "most guys do."
* ''Film/TerminatorSalvation'': a jet pilot, who takes down a flying robot, and who ejects after an engine is shot by the machines which later causes an explosion, is only called "Williams". Marcus goes saving Williams, who is hanging from a telephone tower. Pilot takes helmet off, turns out to be a woman, Blair Williams.
* In ''Film/TheSonOfRobinHood'', Little John has a problem with Robin's heir. Three guesses to what it is.
* In ''Film/TheSting'', [[spoiler:the hitman "Salino" turns out to be ''Loretta'' Salino, the waitress in the diner.]]
* A shocking variant was used in ''Film/HellboundHellraiserII'', in which the gruesome Cenobites are involuntarily transformed back to their original human guises by the Lament Configuration. One Cenobite whose facial features had been burned away, leaving nothing but scar tissue and chattering teeth, is revealed to be [[spoiler:a young boy]].
** This may have been an homage to the infamous use of the same variant in the opening scene of [[spoiler: ''Film/{{Halloween 1978}}'']].
* Subverted in ''Film/WhatsUpTigerLily?'', a Japanese spy movie with new dialog by Creator/WoodyAllen. An escaped prisoner in a head-covering scarf hops into the hero's car and drives off, then pulls off the headgear, revealing herself as a sexy girl. The hero reacts in surprise: "(whistle)... an Oriental!"
* In ''Film/PitchBlack'', [[spoiler:the teenage boy "Jack" is revealed by Riddick, at a conveniently inappropriate moment, to be female. It turns out the blind creatures hunting them are tracing them by their scent of blood, and, although no members of the party appear to be wounded, "Jack" is menstruating.]]
* At the beginning of ''Film/TheScorpionKing'', Mathayus, along with his his half-brother Jesup, and friend Rama, are mercenaries hired by King Pheron to assassinate Memnon's sorcerer, after Pheron learns that the tyrant's victories are a result of the sorcerer's ability to see the future. However, after a difficult infiltration (where Rama is killed and Jesup is murdered), Mathayus discovers that the sorcerer, who he presumed was a man, is a woman named Cassandra. (Who later rescues him and changes sides.)
* ''PocketNinjas'' when the White Dragon at the fight scene near the end was revealed to be Tanya.
* Subverted in ''Film/{{Aliens}}''. Male Marine to ActionGirl Vasquez, as Vasquez does pullups in the locker room: "Hey Vasquez, you ever been mistaken for a man?" Vasquez: "No. Have you?"
* In the film ''Film/TheLastLegion'', familiarity with those trope allows one to quickly surmise that [[spoiler:the Eastern Roman Empire soldier is a chick.]] Why else would she wear a helm with an aventail like that?
* The opening scene of ''Film/IronMan1'' has Tony exclaim in suprise when he realizes that one of his three military escorts is actually female (she's wearing BDUs, ballistic armor and a helmet, so it's hard to tell). She's revealed by her feminine voice the first time she speaks up.
-->'''Tony:''' Good God, you're a woman!
* Quorra's introduction in ''Film/TronLegacy'' has elements of this, as she wears a motorcycle helmet the whole time and even uses a voice modulator. Averted in that it's pretty clear from her outfit that she's a woman, and that the helmet and modulator are intended to hide her identity rather than her gender.
* In ''Film/IndianaJonesAndTheLastCrusade'', Marcus Brody and the title character are somewhat surprised when they learn that their Austrian contact, Dr. Schneider, is actually a woman--her first name turns out to be "Elsa."
* [[spoiler: The Blank / Breathless Mahoney]] in ''Film/DickTracy''. TheReveal is actually quite a TearJerker.
* In {{Slasher Movie}}s featuring female killers, the villain's gender is usually hidden by either a disguise/mask, camera angles, MurdererPOV, or some combination of the three. Plus, they're probably played by random stuntpeople up until TheReveal.
* Related to the above, as Ghostface's trademark in the ''Franchise/{{Scream}}'' films (and the [[Series/ScreamTVSeries TV reboot]]) is to make {{Harassing Phone Call}}s to victims, they always use a [[VoiceChangeling voice-changing filter]] to give themselves a [[EvilSoundsDeep deep, threatening creeper voice]]. This has allowed three women [[spoiler:(Mrs. Loomis/Debbie Salt in the [[Film/{{Scream 2}} second film]], Jill Roberts in the [[Film/{{Scream 4}} fourth]], and Piper Shaw in the TV show's first season)]] to don the mantle of Ghostface over the course of the franchise.
* In ''Film/StickIt'', the hero in the introduction is apparently a cool dude who rides BMX and does crazy tricks. It's only after "he" starts running from the police that "he" sheds his big hoodie to reveal Haley, the female protagonist.
* In ''Film/SkyCaptainAndTheWorldOfTomorrow'', Polly reacts poorly when she meets Sky Captain's old mate, a [[AirborneAircraftCarrier carrier]] captain named Franky. In turns out that Franky's birth name is Francesca. And that Franky is Creator/AngelinaJolie wearing a kickass uniform and an EyepatchOfPower.
* In the Creator/VincentPrice film ''Film/TheatreOfBlood'', Lionheart's lead henchman the British accented guy with the hippie glases, afro, and beard turns out to be his daughter Edwina (Diana Rigg).
* In ''Film/IAmLegend'' Will Smith refers to his dog as "Sam", until just before he has to put it down, when he addresses it as "Samantha". Which could qualify as this.
* In ''Film/YourHighness'', the heroes meet a mighty warrior in the arena, and are surprised when she removes her cloak.
* In ''Film/TheDarkKnightRises'' [[spoiler:the audience (and Batman) is led to believe that the child who escaped from Hellhole Prison was Bane. It turns out that the child was actually Talia, the daughter of Ra's Al Ghul, with her gender deliberately made ambiguous by her short hair and the narration just referring to her as "the child".]]
* In ''Film/{{Colombiana}}'', the police assume that Cataleya's murders were performed by a man, with the lead detective scoffing at suggestions that the killer is a woman because "they had to have been performed by someone with great size and strength". Cataleya uses WaifFu to kill.
* In ''Film/EdenLog'', the botanist turns out to be a woman when the man removes her helmet.
* Comes up early in ''Film/ZeroDarkThirty'' as one of the spectators to the torture is revealed to be female, hidden by a hood.
* Downplayed in ''Film/TheFifthElement'' - the scientist who revives Leeloo assumes that the "perfect" alien he's rebuilding in human shape will be male ("Can't wait to meet him!") He isn't visibly disappointed when he gets an ActionGirl.
* In the 90s ''Film/TheLittleRascals'' movie, the boys are all excited about meeting a UsefulNotes/{{NASCAR}} driver by the name of A. J. Ferguson. They assume A. J. is a man, because [[HeManWomanHater in their minds]], there's no way a girl could do something cool like be a racecar driver. (And also not too many women go by their initials.) When they finally meet A. J. Ferguson, "he" takes off his helmet, only to reveal that "he" is actually a very beautiful woman. The boys are speechless initially, but they are still excited.
* When Hondo and Street go recruiting for Hondo's new SWATTeam in ''Film/{{SWAT}}'', CanonForeigner "Chris" Sanchez is found at the hospital after having beaten the crap out of a GangBanger. Hondo is very surprised to learn that Sanchez (played by Creator/MichelleRodriguez) is a SpicyLatina a good foot-and-a-half shorter than him.
--> '''Hondo:''' Sorry, wrong room.\\
'''Sanchez:''' Who were you looking for?\\
'''Hondo:''' Chris Sanchez.\\
'''Sanchez:''' I'm Chris Sanchez.\\
'''Hondo:''' ''You're'' Chris Sanchez?
* In ''Film/{{Fanboys}}'', the main cast is horrified to learn that one of their closest and most valuable contacts for information, "Rogue Leader", is actually a 10-year old girl. Needless to say, [[PapaWolf her uncle is not too happy with them talking to her]].
* A racial version occurs in ''Film/TheCrazies'' (1973). The sheriff and mayor are startled when the colonel in charge of the GasMaskMooks removes his HazmatSuit to reveal he's black.
* ''Film/FullMetalJacket'': The Viet Cong sniper is a young woman.
* ''Film/TedBundy'': The executioner wears a mask. When Ted is dead, she takes it off.
* In ''Film/GodzillaFinalWars'', Ozaki is assigned to bodyguard a professor who is going to examine a fossil in a remote location. Ozaki starts complaining about having to escort some old coot around, only to be pleasantly surprised when the professor is revealed to be a woman who looks like a model.
* Shura spends the vast majority of her time in ''Film/HussarBallad'' wearing hussar uniform, and every time some other character learns that she is actually a girl, it causes a lot of surprise and disbelief.
* ''Jet Pilot'' (1957). A Soviet jet fighter is forced down on an American base. Creator/JohnWayne is flummoxed when the pilot removes her flight helmet and oxygen mask (with requisite hair flip) to reveal a gorgeous Creator/JanetLeigh.
* Everyone in Camelot is taken by surprise when the Black Knight, a mysterious figure in ''Film/AKidInKingArthursCourt'', reveals that he's actually Creator/KateWinslet.
* ''Film/Momentum2015'' opens with a bank robbery committed by criminals wearing armoured outfits and voice distorting masks. During a struggle their leader's mask comes off to reveal Creator/OlgaKurylenko. Somewhat expected given she's the lead actress, but her gender is well concealed prior to the reveal.

* Britomart in ''Literature/TheFaerieQueene'' has three distinct "Bobs": The reader learns she is a woman after she defeats Guyon, but the first character to learn she is a woman is the Redcrosse Knight, after she saves him from a gang of six other knights. Her love interest is Artegall -- LoveAtFirstSight for her, LoveAtFirstPunch for him.
** Bradamante in ''Literature/OrlandoFurioso'', of whom Britomart is an {{expy}}, does this as well in the... unusual tale of her and Princess Fiordispina.
* In one of the cleverest examples of this trope, Joanne Harris' ''Gentlemen and Players'' has the [[spoiler:narrator]]. This is revealed close to the end of the book.
* Shown to be OlderThanPrint in Literature/TheShahnameh: When Sepid Dejh’s (the white fortress) champion Hojhir challenges Sohrab to single combat, is beaten and taken prisoner, the fortresses chief, Gazhdahm and his daughter Gordafarid realize that the fort will eventually fall. Gazhdahm sends a messenger to Key Kavus, the Shah of Persia through a secret passage and starts to evacuate the city through it, while Gordafarid wears armor, hides her hair under a helmet and challenges Sohrab to buy time. A fierce and long clash ensues and the fight gets closer and closer, culminating in hand to hand combat on horseback. Finally, in the heat of battle Sohrab tears the helmet from Gordafarid’s head and is astonished to [[LoveAtFirstSight realize he’d been fighting a beautiful girl]].
* [[spoiler:Jack]] in Creator/RobertAHeinlein's ''Literature/TunnelInTheSky''. Rod Walker spends several days with her and never guesses. His friend Jimmy deduces the truth after an hour or so of being acquainted. Guess which one she marries.
* Aravis in ''Literature/TheHorseAndHisBoy'' -- Shasta''/''[[spoiler:Cor]] is her "Bob".
* In the ''Literature/{{Hurog}}'' series, Ward's aunt Stala managed to get a decent warrior education before she was found out to be a woman. At one point in the story, a couple of bandits is killed with a small knife. Ward wonders who did it, knowing that the male owner of the farm that was attacked would have used an axe. Later, the badass who did it is revealed to be a woman, who used the small knife because it was the only weapon she had. The little daughter of the house is delighted it was a ''girl'' who did that feat of badassery, Ward only shrugs and says "My aunt could have done the same."
* This happens in one of the ''{{Literature/Flashman}}'' novels, where he and a rebel against the Russian empire are rescued from prison by a group which includes a woman whose face is veiled. He is at first offput when she kisses him, knowing the cultural tradition of male bonding among warriors, but then relaxes when he notices her female attributes.
* Sir George, the knight who saves Princess Andromeda from a dragon in Creator/MercedesLackey's ''Literature/OneGoodKnight'', is actually Georgina.
* Vieve Lefoux in Literature/TheFinishingSchoolSeries by Gail Carringer. While those familiar with Carringer's previous work Literature/TheParasolProtectorate will recognize her as the GadgeteerGenius Genevieve Lefoux, the protagonist is unaware of Vieve's true gender until informed.
* Éponine in Literature/LesMiserables. She's introduced early on the novel, but at one point she disguises herself as a boy and the reader won't discover she's the boy who drove Marius to the barricade until she's [[spoiler:wounded and dying in his arms.]]
* Andre de la Croix in the ''Literature/TimeWars'' series. Also a SweetPollyOliver, but the reader doesn't find out until after she's kicked serious butt at a tournament.
* In Creator/EstherFriesner's ''Literature/MajykByAccident'' trilogy, at one point the hero is rescued by a masked swashbuckler who identifies himself only as "a blade for justice." This eventually turns out to be [[spoiler:the hero's wife, disgruntled at being left at home while he's out on an adventure]]. Even after TheReveal, she [[SweetPollyOliver keeps up the masquerade]], finding swashbuckling to be a rewarding career.
* Éowyn from ''Literature/TheLordOfTheRings''. She does appear previously in the story, but when she disguises herself as a man she's introduced and referred to as a new male character, until she reveals herself.
** In the book, anyway. In the movie, she never introduces herself as the male character and nobody's fooled by the disguise; the director's commentary has Peter Jackson stating that they deviated from the book in that regard because they had to - it was simply impossible to make it convincing and they didn't want to insult the viewers' intelligence with a PaperThinDisguise.
* In ''Literature/ASongOfIceAndFire'', Catelyn watches Brienne of Tarth win a tournament and assumes she's a man because she's encased in plate armor. Because Brienne is hulking, ugly, flat-chested, and often wears warrior garb, she admits to being frequently taken for a man.
** Horribly deconstructed with the story of "Brave Danny Flint" who was raped and murdered by her Nights Watch comrades.
* ''{{Literature/Discworld}}'':
** In ''Discworld/{{Sourcery}}'', [[spoiler:the mysterious thief turns out to be Conina, the daughter of Cohen the Barbarian]]. Although in this case, it's less a matter of bulky clothes, the book simply avoids gender specific pronouns at the start.
** In ''Discworld/MonstrousRegiment'', [[spoiler: everyone]] in the regiment is revealed to be a girl/woman. The readers only know this unambiguously about the main viewpoint character, since the book opens with her deciding to enlist and disguising herself as male to do so.[[note]]It's also not much of a surprise to those who know where the title comes from (A 16th century treatise entitled ''The First Blast of the Trumpet Against the Monstrous Regiment of Women'').[[/note]] The other members vary from "yeah, obvious" to "wait, I thought the big secret [name] was hiding was being a [vampire/werewolf/whatever]."
** The [[spoiler: noble dragon]] in ''Discworld/GuardsGuards'' is one, too.
** In ''Discworld/FeetOfClay'', it's revealed that [[spoiler: Cheery Littlebottom]] is a female dwarf to the reader fairly quickly. As a lampoon on OurDwarvesAreAllTheSame, Dwarfish culture is [[strike:so male-centric that females typically behave and masquerade as men]] stated that all dwarfs are considered dwarfs without distinction of sex. This can cause confusion when two dwarfs like each other and need to delicately find out if they have met a friend or a mate. Angua detects her secret and coaches her to slowly adopt feminine behavior, which causes a lot of confusion among her other co-workers. She ultimately comes out of the closet and [[spoiler: renames herself Cherry.]] She also starts wearing dresses. Chainmail ones with an axe... she said she was ''female'', she never said she wasn't a ''dwarf.'' She also keeps her beard for the same reason.
** Carrot himself is shocked when Angua mentions that one of the other Watch dwarfs is female as well, albeit still closeted.
** Subverted earlier in the series as well. When Angua is introduced in ''Discworld/MenAtArms'' (''But she's a w...''), it is [[MostCommonSuperpower obvious right away that she is female]], but it's not until later that the reader finds out that she is a ''werewolf'', and some of the characters don't find out until the end.
* "Once and Future", a non-''Literature/{{Discworld}}'' story by Pratchett available in the collection ''A Blink of the Screen'': the lost heir of Uther Pendragon is revealed to be female only after she has pulled the sword out of the stone and been declared the true king. She knew enough about sexism in her society to keep that a secret until it was too late.
* Creator/TamoraPierce plays with this trope a bit. The readers know very well that [[Literature/TortallUniverse Alanna/Kel]] is a girl (especially [[SweetPollyOliver Alanna]]); it's the various characters who get the shock.
* Matt Ruff's ''Literature/SetThisHouseInOrder'' when we find out [[spoiler:that despite the personalities of the first person narrator being predominantly male, the body is female]].
* P. Berling's "Die Ketzerin" ("The Heretic") begins with a knight tournament, and the winner is a woman, namely the main heroine.
* [[spoiler:Joat ("Jack-of-all-Trades")]] in ''Literature/TheCityWhoFought''.
* [[spoiler:The mysterious armored warrior]] in Grace Chetwin's YA series, ''Gom Gobblechuck''.
* ''Literature/TheCoronation'': Fandorin's [[spoiler:ArchNemesis [[DiabolicalMastermind Dr. Lind]]]] is revealed to be a girl in the final showdown, who kept her tightly-knit gang together ''with ThePowerOfLove''.
* In the ''Franchise/ConanTheBarbarian'' story [[spoiler:''The Flame Knife'']] Conan is forced to leave a battle because of additional forces coming in for their own reasons. While trying to work out how to extract the girl who was hiding in a building the far side of the battlefield, one of his soldiers tells him it's taken care of and takes off "his" helmet.
* Crackers, George and Harold's pet pterodactyl in some of the ''Literature/CaptainUnderpants'' books, likely falls into this. After being hypnotised (along with Sulu the bionic hamster) into being evil, Crackers in fact does good. It was previously established that the doohickey that does the hypnotising causes females to do the opposite of whatever they are commanded to do. Plus, all of the pronouns relating to Crackers are highlighted-a fact which George and Harold notice.
* ''Literature/HarryPotter'': Norbert the Norwegian Ridgeback is revealed to be female by the series' end. In light of this, her name was changed to Norberta.
** The tie-in book ''Fantastic Beasts and Where to Find Them'' says that male basilisks have a scarlet plume on their head, identifying the basilisk in the second book as female.
* Director Inoue Sato in Creator/DanBrown's ''Literature/TheLostSymbol''. No awesome armor, but a surgically raspy voice and a cell phone connection do the trick.
* [[spoiler:Maugin]] in ''Literature/TheEdgeChronicles''.
* In ''Literature/FromRussiaWithLove'', Creator/IanFleming goes into detail describing the hideous appearance of DirtyCommunist Rosa Klebb, before ending with the words "She pulled up her skirt and sat down".
* Kitai from ''Literature/CodexAlera'' gets this ''twice''. From the same person.
** In the first book, Kitai is an adolescent Marat (a neanderthal-like human) without any secondary sexual characteristics. Her father calls her, and all adolescent Marat children "whelp." It isn't until she falls in some cold water and lifts her loincloth to keep it dry did Tavi see she lacks male genital.
** In the second book, it has been two years since the first one, and Tavi is studying in the capital city and tasked with finding a mysterious burglar who is getting past the magical defenses. Tavi, as th P.O.V character, uses male pronouns when thinking about the criminal, only to change when he finally catches her.
* In Robert J. Sawyer's ''CalculatingGod'', [[spoiler: the main character (and the reader), are surprised to learn that the alien he has been working with is female.]]
* In one of Akutagawa's short stories, "The Martyr", the young man who was adopted by the Catholic church had been assigned the name "Lorenzo". Later, "he" was excommunicated from the Catholic church because a girl accused "him" of fathering her child. After "he" had saved her child from a burning house and the mother revealed the truth about the child's paternity, Lorenzo was revealed to be a woman all along. This was based loosely off a true story: [[http://maroniteinstitute.org/MARI/JMS/july00/Saint_Marina_The_Monk.htm Saint Marina the Monk]]
* Lampshaded straightforwardly in John Nichol's novel ''Point of Impact'', in which Jane, a female member of aircrew, is advised, after stepping down from an aircraft, to remove her helmet and shake out a mane of blonde hair - and she does. Nichol is an ex Tornado navigator famous for failing to set up an aircraft correctly on the final run into an Iraqi airbase in January 1991; understandable mistake, but not really the time to make it since the blunder earned him and his pilot a multi-week stay at the pleasure of the Iraqi regime and their baseball bats. Ironically, Nichol probably left the RAF around the time female fast-jet aircrew began to appear.
* In Creator/PatriciaBriggs' ''When Demons Walk'', Sham is often mistaken for a pubescent boy, a resemblance she augments with masculine dress and hair. Kerim has an entire conversation with "him", Talbot watches "his" interrogation, and when Kerim is attacked Sham throws the knife that kills the attacker. When they try to find him again, they can't figure out how he managed to disappear so completely, until an amused informant finally reveals that they should start asking about local ''women''.
* At a Worldcon panel, an anecdote about an accidental, out-of-story example from ''Literature/TheHungerGames'' was discussed: The author, Suzanne Collins, works as a teacher, and at one point a boy in her class, who was most of the way through the first book, gushed about Katniss to her, saying "He's so cool!". Collins pointed out that Katniss was a girl, to which the boy responded, [[StayInTheKitchen "Girls don't hunt!"]]
* This is the TwistEnding of ''The Turbulent Term of Tyke Tiler'' by Gene Kemp. [[spoiler: Throughout the book, [[NaughtyIsGood goodhearted troublemaker]] Tyke has been the narrator, so [[TheAllConcealingI we don't get any gender-specific pronouns]] and only occasional references to "[[EmbarrassingFirstName my real name]], [[DoNotCallMePaul the one I hated]]". It's only at the end, when Tyke climbs the roof of the school in imitation of possible ancestor Tom Tiler, that we hear a teacher screaming "Theodora Tiler, you naughty, disobedient girl!"]]
* In ''Videogame/StarWarsTheOldRepublic: Fatal Alliance'', Dao Stryver is a tall, tough [[ProudWarriorRaceGuy Mandalorian]] wearing full body armor and helmet. The novel consistently refers to Stryver as "he." He has a deep, male voice, filtered through his armor. At the end, Stryver turns out to be a [[LizardFolk Gektl]] female, although one character knew it all along. Since most Mandalorians shown in films and games tend to be male humans, this was a big shock. This is even more jarring in the audiobook, where the narrator makes an effort to make Stryver to sound like a tough guy, using special effects to add to the feel of the character. Then comes the Gektl female with {{Sssssnaketalk}}.
* John Jackson Miller avoids pronouns when it comes to the Tusken warrior A'Yark in ''Literature/StarWarsKenobi'' until halfway through the novel, he starts using feminine pronouns for the character. The other characters learn A'Yark's true identity later.
* In the Literature/CiaphasCain novel ''Duty Calls'', Cain is saved by a warrior in PoweredArmour who turns out to be Amberley Vail. It's not her first appearance, but the unidentified warrior is separately established under that description before the reveal.
* In Creator/IainBanks's ''Literature/TheWaspFactory'', [[spoiler:the ''protagonist himself'' only finds out at the end that he is physically female. He was attacked by a dog in childhood, and his father claimed that the dog had castrated him. His father fed him male hormones in the meals.]]
* In the first in the ''Literature/AToZMysteries'' series ("The Absent Author"), our detectives try to get reclusive mystery author Wallis Wallace to show up. Wallis doesn't show up, but the gang finds him kidnapped... [[spoiler: then realizes Wallis is really tourist Mavis Green, and the kidnapped man is her brother, Walker.]]
* Literature/JirelOfJoiry is revealed this way in her first story "Black God's Kiss".
* In Creator/JamesHerbert's ''Nobody True'', the ghost protagonist spends a lot of time stalking a hideously deformed serial killer with psychic powers named Alex, and even ends up possessing the killer's dead body to use it to save his family...only to find that Alex was short for Alexandra, and she was too deformed to notice her breasts. Alex even walked like a man.
* In ''[[Literature/FirebirdTrilogy Firebird]]'', Brennen Caldwell initially assumes Firebird Angelo is a man, simply because she was a pilot in the attack phalanx of the Netaian invasion force. His assumption is corrected after she is captured.
* In ''Literature/{{Icerigger}}'' by Creator/AlanDeanFoster, it's not revealed that [[spoiler: Sagyanak the Death]] is female until well after the Horde has been driven from Sofold.
* Boba Fett's estranged daughter Ailyn Vel impersonated her father for a period of time. So deadly and ruthless was she that everyone who met her during this period thought she really was her father--but her utter lack of ethics went beyond even Fett's harsh methods, and years later the truth was eventually discovered.
* In ''Literature/TheBlackCompany'' novels, Soulcatcher, one of [[QuirkyMinibossSquad the Ten Who Were Taken]] is an interesting example. It's well known that three of the Taken are female, but owing to the Taken's habits of concealing their true features, no one's quite sure which and just call them all "he" indescriminately. Soulcatcher herself further confuses matters by the fact that her voice changes continually to reflect the souls she's stolen, so her voice is sometimes male, sometimes female. However, it ''is'' noted that Catcher's masculine clothing doesn't fully conceal her shape and "he" has fairly effeminte mannerisms- at the end of the first book, Catcher's ubiquitous helmet comes off and she's revealed to actually be a woman. Later in the series she makes no attempt to disguise her gender, even when hiding her face.
* ''Literature/TheStormlightArchive'': Several examples. This is helped by the extremely strict gender roles of the Vorin religion. The idea of a woman fighting is as inconceivable as [[DeliberateValuesDissonance a man writing a book]].
** ''Literature/TheWayOfKings'': In one of Dalinar's visions of the past, he is shocked when one of the Knights Radiant turns out to be female. No one in the vision finds this at all odd. Later, he inspects one of the Parshendi warpairs, and comes to the conclusion that the clean-shaven "apprentice" of the pair is actually female. It helps that Parshendi are covered in carapace armor while in warform, and have very small breasts except in mateform.
** ''Literature/WordsOfRadiance'': At the end of the previous book, Dalinar fought the last Parshendi Shardbearer, who was obliquely named Eshonai (it was the name of the chapter, but never actually came up in the text). When Adolin runs into Eshonai after a plateau run, he is flabbergasted when he realizes she is female. Again, the armor helped conceal her gender, plus her thick accent.
* ''Dead Mountaineer's Hotel'' by Creator/StrugatskyBrothers has Brun "The child", a teenager of ambiguous gender who wears unisex clothes, large shades and avoidance of gender endings in words). [[spoiler: Her full name is Brunhilde]].
* In ''Literature/TheDresdenFiles: Literature/ColdDays'', the fairy Dresden nicknames "Captain Hook", for wearing an armor made of fishing hooks and nearly took his eye out, is revealed to be a girl named Lacuna after she is captured by the heroes and her armor comes off.
* Chops the gremlin of ''Literature/CityOfDevils'' is assumed to be male, due to her lush muttonchop sideburns. She is revealed to be female only after Nick Moss views the film of her creation.
* Brady in ''Literature/MrBlank'' disguises herself as a man -- a garden variety government spook, complete with sleazy blond mustache -- in order to double dip among several conspiracies.
* Jack in the UsefulNotes/NaNoWriMo novel ''Literature/AndThenThereWereMonsters'' turns out to be short for Jacqueline. Of course, it takes place in the 12th century, where such a thing is pretty much literally unthinkable.
-->'''Wreth:''' No wonder you go by Jack. I have never heard of anyone named Jacqueline who was not a [[ExplainExplainOhCrap giiirl oh crap]].
* In ''Literature/ThoseThatWake'''s sequel, the Librarian is revealed as a girl.
* Creator/JaneYolen's ''Sword of the Rightful King,'' a KingArthur retelling, has an interesting twist when [[spoiler:the apparent CanonForeigner Gawen, Merlinnus's teenage assistant]] turns out to be a young noblewoman named [[spoiler:Guinevere]].
* An internal short-term version is seen, or rather read, in ''[[Literature/{{Temeraire}} Blood of Tyrants]]'' when an amnesiac Laurence checks the correspondence in his cabin for clues as to the eight years he is missing. As he reads one letter from an Aerial Corps Admiral stationed on the Spanish front, he rapidly generates a mental image of the writer; a working officer in his mid-forties, confident in his judgement and secure in his position, indifferently educated by [[OfficerAndAGentleman his own]] standards[[note]](being reared far from society from childhood, like most aviators, meant that allowances must be made)[[/note]], but clearly a good friend of his and close kin of his Midwingman Emily Roland. This mental image is shattered, despite every particular but one unspoken assumption being correct, when he reaches the signature: "Yours, etc., Jane."
* Veckert Rainer in ''Literature/{{Distortionverse}}'', much for Kari's dismay.
* In the ''Literature/TowersTrilogy'', Lorn tells Xhea of an assassin who killed many members of Edren during the last war. Everyone assumed that the assassin was male, but Xhea later learns that the assassin was in fact her mother, Nerra.
* While the audience finds out that Mach from ''Literature/RumorsBlock'' is a girl, most of the main cast still doesn't know. And those that do still refer to her as 'he' during conversation.
* ''Sidekicks'' by Jack D. Farraiolo is a [[SuperheroLiterature superhero novel]] where the main character, Scott/Bright Boy, has a rivalry with supervillain sidekick Monkeywrench. It's only after "his" mask comes off in a fight that Scott realizes Monkeywrench is a popular girl from his school (who quickly also [[DatingCatwoman becomes his]] LoveInterest). Well, that explains the high voice and new, less form-fitting costume...
* Another [[SuperheroLiterature superhero novel]] called ''Geeks, Girls and Secret Identities'' has the protagonist, Vincent, learn that his local superhero, Captain Stupendous, is a.) a HenshinHero and b.) [[GoodBadGirl Polly]], the girl whom he has a crush on. In this case, however, she actually just [[LegacyCharacter inherited her powers]] from the first Captain Stupendous, who was their male teacher.
* A reader picking up LawrenceWattEvans' ''Literature/NightsideCity'' and starting on the first-person narrative would immediately understand that this is a HardboiledDetective mystery, with all the typical attributes of the genre - even if it takes place on the exotic background of a future interstellar civilization. But it takes several pages before the first-person narrator casually lets slip the fact that she, Carlisle Hsing, is a woman detective.
* In Creator/JohnVarley's ''Literature/TheOpiuchiHotline", taking place on the Moon and in the Asteroid Belt during the 27th Century, the dissident scientist Lilo is trapped - seemingly hopelessly - in the nefarious schemes and plots of the powerful corrupt politician calling himself "Boss Tweed". The demagogue and blatantly macho Tweed consciously emulates the corrupt politicians of late 19th Century America, even to renaming the Lunar Presidential Mansion as "Tammany Hall". Tweed's trademarks are his paunch, pin-striped suit and top hat - all hopelessly archaic in the 27th Century but beloved by Tweed's grassroots following. In the book's cataclysmic end, Lilo turns the tables and Tweed is unmasked and is wanted for several heinous crimes, each carrying a mandatory capital punishment under Lunar law. However, Tweed had a contingency plan for this eventuality, too. He goes into a deserted tunnel deep under the Lunar surface and undresses. He lets fall his paunch, which had been no more than a kind of artifical attachment developed by 27th Century medical science, and the true Tweed is shown to be tall and slender. The paunch falls on the floor and chemically self-dissolves. It is immediately followed by Tweed's penis, which had also been no more than an artificial attachment (though bio-engineered to seem like the real thing). Where it was is revealed a female sexual organ which had been kept hidden for many decades. Boss Tweed was a woman all along.
* In ''Literature/WarrenTheThirteenth'', Paleface, the {{Bandaged Face}}d stranger is revealed to be [[spoiler:Petula]]'s mother.
* In the first tome of {{LightNovel/Zaregoto}} the name of [[TheAce Aikawa Jun]] but the main character assumes she's male. Turns out wrong at the end of the book.
* {{Downplayed}} in ''Literature/{{Animorphs}}:'' in one of the last books, the team has to see the governor, and narrator Marco admits that he doesn't know much about "him." The governor is a woman. (For what it's worth, an earlier book established that their state had a male governor, but then, a few years have apparently passed in the meantime.)
* In the ''Literature/InspectorMorse'' short story "Neighbourhood Watch", Morse and Lewis stake out a house where Morse is sure there's going to be a burglary, the burglars having ensured the victim is out for the night, and see nothing more suspicious than a woman delivering free newspapers. It later transpires the apparent victim had ''also'' deduced he was being targeted, but had taken it a step further: he knew [[IKnowYouKnowIKnow that the burglars knew Morse knew]], and had therefore changed their plans. Just in case he was wrong, he also hired a private detective to keep an eye on things, whom he describes to Morse as a judo black-belt who could easily have taken care of any trouble. Morse is surprised they didn't spot him, and the victim corrects him; ''she'' was the paper woman.
* In ''Literature/FortunatelyTheMilk'', [[spoiler:the narrator-protagonist goes on an entire adventure with the eccentric inventor Professor Steg before they meet another of the Professor's people who casually mentions that Professor Steg is female. The protagonist does at least have the excuse of Professor Steg being an entirely different species with none of the usual human gender indicators, but he's still embarassed to realize he automatically assumed that an adventurer-inventor would be male]].

[[folder:Live-Action TV]]
* ''Series/GameOfThrones'': Brienne of Tarth defeats reknowned knight Loras Tyrell to win a tournament before removing her helmet to reveal she is a woman to the viewers and the crowd, which elicits gasps.
* ''Series/StargateSG1'':
** Vala Mal Doran is revealed this way in "Prometheus Unbound" . Downright hilarious when she starts trying to seduce Daniel while wearing the armor of an artificially engineered monster super-soldier, and with her voice masked to match... A bit of a variation in that ''Vala'' was the one who attacked the ship and captured Daniel. This is probably a ShoutOut to Claudia Black's previous role in ''Farscape'' (see below).
*** Daniel: "Sorry, you're not my type, and I'm a more than a little disturbed to think I might be yours." *helmet comes off, revealing Claudia Black* Daniel: "Um...oh..."
** In the pilot episode, General Hammond mentions that he has assigned Captain Sam Carter, their top Stargate expert, to Colonel O'Neill's team. Col. O'Neill asks where ''he'' is transferring from. From the door, Captain Carter tells him that ''she'' is transferring from the Pentagon.
* ''Series/StarTrekDeepSpaceNine'':
** In the episode "Rules of Acquisition", Quark works very closely with a Ferengi waiter named Pel in his bar for a job given to him by the Grand Nagus. Pel proves to be extremely talented at business, giving Quark many ideas to make a lot of money from the job. Pel later hits on Quark and kisses him, and the moment is played for laughs. But then later you see Pel in "his" quarters, taking off ear prosthetics and a garment that disguises her figure, revealing that she is actually a Ferengi woman. She disguised herself as a male because in Ferengi society it is illegal for females to earn profit. Incidentally, Pel is portrayed by a woman in ALL appearances, including the ones where she is disguising her voice to sound male, but you can't really tell under the Ferengi prosthetics.
* ''Series/{{Farscape}}'':
** Aeryn Sun (also played by Claudia Black, incidentally) is first seen as a fearsome person in a bulky, black, armored spacesuit with a smoked-glass helmet, on a spaceship full of bizarre alien creatures. Off comes the helmet...and you see a fearsome, angry (but attractive) woman in an armored spacesuit.
** While no helmet or concealment is involved, in the episode "The Flax" one very masculine-looking Zenetan pirate (played by a male actor) is revealed to be female of her species by the end of one Farscape episode. In their race, both genders look androgynous, and a female can pass as male.
* In ''Series/KamenRiderFaiz'', Kamen Rider Delta was revealed to be a woman encountered by the cast previously (until then, we'd also never seen Delta in real action; just baddies getting wasted and Delta standing there). In an example even worse than the Zelda one, she's just about to suit up for the first time since we found out who she was and have her first onscreen fight scene... when she's ''impaled'' by a villain and her armor taken and used by another. (The ''Franchise/KamenRider'' franchise, either because of tradition or [[ValuesDissonance extreme and utterly shameless sexism]] -- hopefully, the former -- has had exclusively male heroes since [[Series/KamenRider it began in the 1970s]], with the rare exceptions eventually being [[StuffedIntoTheFridge executed by the plot]] for their audacity. Nobody savvy about the franchise expected her to survive long, though getting to see her in action once would've been nice.)
** They did have ''another'' female transform into Delta. For about five seconds... then she gets hit once and de-transforms. Japan just changes very slowly,simple as that.
** Ironically (and probably even more sexist), the Riders who we know are women from day 1, or who are evil, don't last long either, but they do last longer than any and all cases of Samus Is A Girl.
** In ''Series/KamenRiderFourze'', [[spoiler:the Scorpio Zodiarts is revealed to be female, despite having a male voice and fake hints being dropped that various male characters were Scorpio. However, Japanese-speakers may have noticed the SignificantAnagram: Sarina Sonoda = Sasori na no da = "I am the scorpion."]]
*** [[spoiler: Inverted in case of Virgo Zodiarts, when her true identity is Emoto ''himself''. Despite that, similar with Sonoda, his name has [[SignificantAnagram significant]] [[SdrawkcabName backwards name]] of otome, which is "virgin" in English.]]
* No mortal peril involved (and probably no relationship, but this is [=MacGyver=] we're talking about), but a female T-38 pilot does this on an episode of ''Series/MacGyver'' after she gives Mac a free flight. Get your minds out of the gutter...
* The (classic) ''Series/KnightRider'' episode "Buy Out" starts with Michael seeking out a "Mel" at a factory after Devon's assignment briefing. He goes to the factory where sent, spots a worker with a blowtorch with the name tag "Mel." Turns out it wasn't "Melvin," as Michael had initially thought, but "Melanie."
* The opening of the ''Series/{{Witchblade}}'' TV show had a figure going about his day - putting on his boxer shorts, putting on his leather jacket, and getting on his motorbike, before 'he' takes off his motorcycle helmet and it's a woman.
** Doesn't help that there's such thing as women's boxers.
* The 2006 series of ''Series/RobinHood'' tries to pull this off with the identity of the Night Watchman, but doesn't quite manage it.
** It also does something similar with Djaq - the first confirmation the astute audience get of her gender is Will walking in on her naked (ritual cleansing pre-prayer in fact). [[spoiler:Considering later events, it makes it a [[NakedFirstImpression naked second impression]] as the two become canon.]]
* In one episode of Chris Titus', um, ''Series/{{Titus}}'', his girlfriend's niece and ward Amy is distraught over her breakup with "Charlie." After an episode-long flashback to the title character's high school days, Titus' girlfriend shows "Charlie" in. It's a girl.
-->'''Titus''': ''[smiling confusedly]'' Ch-Charlie. That's one of those trick names. So that means...\\
'''Amy''': -I'm a big fat [[NWordPrivileges dyke]]? ''Yeah.''
* ''Series/PowerRangersSPD'': [[spoiler:the Red Ranger of the SPD A-Squad]]. Double points for [[spoiler:having the TomboyishName Charlie]]. This actually caused a bit of a stir on the Rangerboard forum: one member, being an expert in digital voice manipulation, [[spoiler:guessed -- and posted -- that he thought A-Squad Red was a girl. Then comes the reveal, and he was not. Modest. At. All. He ended up printing a t-shirt of Charlie that said "I was right!" and got several SPD cast and crew members to sign it.]] CrowningMomentOfAwesome?
** They ''tried'' pulling this off again in ''[[Series/PowerRangersRPM RPM]]'' with Dr. K (key word being ''tried''), but it failed for two big reasons: One, the voice distortion she used still sounded too feminine, and two, a trailer that got leaked showed a girl with the label ''Dr. K''. And even then, this isn't getting a spoiler tag because the reveal happened in episode 4!
** It's also done in ''Series/PowerRangersNinjaStorm'', in the second part of the episode "The Samurai's Journey", with Cam's mother Miko. Cam travels back in time to find a new power source, and sees how his parents met - his mom was the first female student at their NinjaSchool, a fact his dad only learned after she publicly kicked his ass.
* ''Series/KyleXY'': [[spoiler:[=AndyJ=]]].
* From the ''Series/{{Bones}}'' episode "Fire in the Ice", Albie the poker ring organizer. Booth is very shocked. Perhaps because he recognizes her from his ''Series/{{Buffy|the Vampire Slayer}}'' days?
** The recurring villain the Gravedigger is referred to by male pronouns until [[spoiler: Her identity as Heather Taffett is revealed]]
* ''Series/HowIMetYourMother'' has an example in the episode "Jenkins". Marshall is constantly describing the hilarious exploits of his coworker Jenkins, and he lets his friends visualize Jenkins as an older, vaguely overweight man in order to avoid making his wife jealous. It turns out Jenkins is an attractive woman Marshall's age, and this revelation leads to all the main conflict of the episode.
* Subverted in the first episode of ''Series/GetSmart''. We can tell Agent 99 is a girl, it just takes Max a while to realize it.
** A funnier one occurs in a later episode where Max agrees to host a scientist who has the power of invisibility at his house while 99 (now married to him) is on vacation. He then finds out after the scientist becomes visible that the scientist is female (and even the Chief didn't know!). Now he must deal with hosting a female while his wife is out (think about how that would look to others). It gets worse when 99 comes back from her trip early and accuses him of cheating when she finds him; thankfully they sort it out.
* A textbook example, from a second season episode of ''Series/{{Merlin}}'', we see [[spoiler:a sorceress, played by Emilia Fox, being all sorceress-y. We then see someone in a full suit of armour waltz through Camelot, kill five guards, enter the Great Hall, challenge Arthur to a duel, ''then'' remove her helmet, shake out her long blonde hair and reveal... Emilia Fox]].
* ''Series/{{Doctor Who}}''
** "[[Recap/DoctorWhoS25E1RemembranceOfTheDaleks Remembrance of the Daleks]]": [[spoiler:The Renegade Dalek battle computer is the young girl constantly seen beforehand.]] Made more effective by having a voice of the opposite gender before TheReveal.
** "[[Recap/DoctorWhoS32E1TheImpossibleAstronaut The Impossible Astronaut]]": [[spoiler:The eponymous astronaut is the little girl who is constantly phoning UsefulNotes/RichardNixon for help.]]
** "[[Recap/DoctorWhoS3E4TheDaleksMasterPlan The Daleks' Master Plan]]": Mavic Chen and his aide decide to call out their toughest Space Security Agent to apprehend the Doctor and company. It takes several scenes before we establish that "Kingdom"'s full name is "Sara Kingdom."
** Played for tragedy in "[[Recap/DoctorWhoS28E6TheAgeOfSteel The Age of Steel]]": An unwillingly cyber-converted human rambles deliriously about her wedding plans.
* In the less than impressive sequel to the ''Series/{{Merlin 1998}}'' MiniSeries, ''Merlin's Apprentice'' Squire Brian turns out to be Squire Brianna.
* ''Series/{{Blackadder}}'': "I always thought that Jamie and Angus were such fine boys." "Angus is a girl."
** The ''Blackadder the Third'' episode "Amy and Amiability" has a subplot involving a mysterious highwayman called "The Shadow". It turns out to be Amy Hardwood, a woman he had earlier tried to fix the Prince Regent up with.
* ''Series/HomicideLifeOnTheStreet'': Lewis' first reaction to Det. Teri Stivers in Season 5 is reminiscent of this.
-->'''Lewis:''' Which one of you is Stivers, I'mma slap you.\\
'''Stivers:''' I'd like to see you try, pal!
* In the pilot episode of ''Series/LasVegas'', Danny looked all over town trying to find the mysterious casino host, Sam. He only found out Sam was female after she'd already pumped him for information, posing as her own secretary.
* In the fourth season of ''Series/{{Solitary}}'', Number 3 was in their early twenties, and an ex-high school football player. And she was a girl. While the viewer knew from the start she was female, all the other numbers thought she was a boy. Number 3 eventually made it to the final three (and eventually won), which is when the other two finalist (2 and 6) found out she was a girl. They were a bit surprised.
* Season 2 of ''Series/{{Warehouse 13}}'' features [[spoiler:[[Creator/HGWells Helena G. Wells]]]].
* In ''Series/{{Psych}}'', [[spoiler: the terrifying SerialKiller Mr. Yang]] is revealed to be [[spoiler: played by Ally Sheedy]]. The surprise of the Reveal is slightly more justified than most cases of this trope, in the defense of the main characters, what with her [[spoiler: very clearly presenting herself in her letter as MISTER Yang, not just Yang or anything gender-ambiguous. Who says VillainsNeverLie?]]
** Arguably subverted/justified in the second sequel to that episode, when [[spoiler:her loveless father and counterpart, Mr. Yin, is revealed to have been the evil one; she was reluctantly raised to comply with his commands, and was forced along for the ride.]]
* In the first scene of the pilot of ''Series/LoisAndClark'' a young man with a mustache and beard enters the Daily Planet. He sits down at a desk, then removes the disguise to reveal that he is actually Lois Lane, who was working on an undercover story. Lois also cross-dresses in a season 2 episode, where neither her boss nor Clark recognize her immediately.
* Ziggy Vadas from ''Series/{{Life}}''.
* ''Series/{{Community}}'': Greendale's Human Being mascot is revealed to be portrayed by a female student during a webisode.
* In ''Series/{{Castle}}'', [[spoiler:Lone Vengeance]] is revealed to be a previously unsuspected woman.
* In the first ''Series/HerculesTheLegendaryJourneys'' episode/pilot movie, much suspense is made of the nature of the "beasts" and the eventual dramatic reveal that they are, in fact, women. This would be much more dramatic if the episode weren't called ''[[SpoilerTitle Hercules and the Amazon Women]]''.
* In the ''Series/{{Angel}}'' arc where they go to the demon world of Pylea, the gang meets Lorne's parent, who's played by a tall, muscular, bearded man with a deep voice. When Lorne refers to this demon as "Mom", Angel does a DoubleTake and mouths, "Mom?" Hard not to blame him.
* ''Series/OnceUponATime'':
** Mulan is introduced this way in the Season-2 premier, initially being a mysterious armored figure.
** In a flashback, Prince Charming is robbed by a mysterious stranger in a cloak. He pursues the stranger, and realizes she is in fact a woman, Snow White.
* ''Series/PersonOfInterest'': Until the season 1 finale, "Firewall," the only thing we knew for certain about Root was that she is a woman.
* InUniverse on ''Series/{{Dollhouse}}:'' [[ReluctantMadScientist Topher]] had long been fascinated with the research of [[BrokenBird Bennett Halverson]], but the GenderBlenderName apparently kept him from realizing his idol was a woman. A young, attractive woman [[GeekyTurnOn who wears librarian glasses around her neck]]. The truth makes him [[IfItsYouItsOkay even more]] infatuated with her!
* Ross on ''Series/{{Friends}}'' initially assumes Charlie, another professor, is an older, stuffy man before he meets her, based on other professors he has met. When he meets her, he is pleasantly surprised that she turns out to be a attractive woman, and she becomes his love interest.
* ''Series/{{Elementary}}''[='=]s Moriarty is a villainous example, only being revealed as a female long after her name is first heard. Most of her {{Mooks}} even think she's male.
-->'''Sherlock:''' So who [[TheVoice is the man I spoke to on the phone?]] [[TheGhost The man who said he was Moriarty?]] \\
'''Moriarty:''' You talked to one of my lieutenants. He has over the years played the role repeatedly and with great conviction. More often than not he has done so to protect my identity. Other times it was because I suspected some potential clients might... [[StayInTheKitchen struggle]] with my gender. As if men has a monopoly on murder.
* In the pilot of ''Series/{{Chuck}}'', a ninja is caught trying to steal Chuck's computer by Chuck and Morgan. After a fight that results in the destruction of the computer (and Chuck and Morgan's pride), the ninja races away. Later, it removes its mask, revealing the beautiful woman who'd been flirting with Chuck at the Buy More earlier in the episode.
* America's Best Dance Crew'' In the sixth season finale, the {{Jabbawockeez}} performed and they were joined by a [[http://www.youtube.com/watch?v=blr2B2Wkndw little dancer]], [[spoiler: who is revealed to be a little girl.]]
* The plot of ''Series/PrisonBreak'' is kicked off when central character Lincoln Burrows is framed for murdering the brother of the Vice President of the United States; it takes several episodes before we learn that the Vice President is actually a woman. Interestingly, the show manages to pull this trope off in reverse: early in Season 1, we get several glimpses of a sweet-faced suburban woman tending her garden (listed as "Garlic Cutter" in the credits) who's connected to TheConspiracy in some way. Her identity doesn't become clear until [[WhamLine someone addresses her as "Madame Vice President"]].
* In ''Series/{{Jessie}}'', Ravi's lizard Mr. Kipling is revealed to be a ''Mrs.'' Kipling in the Season 1 finale.
* ''Series/RoundTheTwist'': Ariel, the subject of the fourth season's HalfArcSeason.
* According to WordOfGod, Dark Faust is this in ''Series/UltramanNexus''. It doesn't help that she is voiced by Creator/TetsuInada.
* In ''Series/TheBlacklist'', Elizabeth is surprised to learn that Reddington's lieutenant and [[CleanupCrew cleaner]] "Mister Kaplan" is actually a woman. Her OriginsEpisode later reveals that this alias is a tribute to her dead lover.
* In ''Series/{{Westworld}}'', the central character of Ford's new narrative is a mysterious host by the name of Wyatt, an Army sergeant who supposedly came back from the wilderness with "some strange ideas" before massacring his old unit and recruiting other hosts to his cause. [[spoiler:In reality, Wyatt is one of Dolores' personalities, originally uploaded by Arnold so she would kill all the hosts in the park [[ThanatosGambit and then Arnold himself]] to force the park to shut down. 30 years after that plan failed, the Wyatt personality resurfaces as Dolores gains true consciousness (with some secret assistance from Ford) and leads the hosts in an [[RobotWar uprising]] against humans.]]
* In the ''Series/MiamiVice'' episode "The Fix," Switek is surprised to discover that the drug dealer Ortega is a woman.

* The music video for Music/TheProdigy's "Smack My Bitch Up". The reveal is at the end when the camera (from a first-person perspective) looks at a mirror. Before this she went to a bar, got drunk, beat up patrons and groped hot girls before returning home and passing out in front of a mirror.
** A similar "woman doing manly things only revealed to be a woman at the end" music video is Bush's "Machinehead".
* Turkey actually used this in their performance in the Eurovision Song Contest 2010, "We Could Be the Same" by [=maNga=]. [[http://www.youtube.com/watch?v=XjULJg4Ce6M Watch it here.]]
** They must not have been trying that hard, because one good look at the figure makes it really obvious what her gender is.
* The trance artist formerly known as Hybrid Factor was originally [[TheInvisibleBand pictured as]] Steve Bailey, but later revealed to be Aimee, his sister. She now goes bt the artist name Aimee B.
* Many promotional videos of the British Invasion band The Honeycombs attempted to hide the fact that their drummer, Honey Lantree, was female until some point later in the film clip (most notable is their performance of "Have I The Right?" in the 1965 concert film ''[[http://en.wikipedia.org/wiki/Pop_Gear Pop Gear]]''. They then do the ''[[ViewersAreGoldfish same damn thing]]'' the next time they appear in the film, performing "Eyes")
* The [[http://www.youtube.com/watch?v=Dy6MpsDPKts music video]] for the Music/WithinTemptation / Music/{{Tarja}} song "Paradise" features a pair of survivors in a post-apocalyptic wasteland trying to restore life to the planet. In the end it's revealed they are both women.

* In ''Pinball/CirqusVoltaire'', when you unmask Voltaire, not only is Voltaire revealed to be a woman, she is also the game's announcer.

[[folder:Pro Wrestling]]
* Shantelle Malawaski, best known for her work in various independents as Shantelle Taylor and in Wrestling/{{TNA}} as Wrestling/TaylorWilde, wrestled two house show (non-televised events) and one dark match (non-televised matches held before televised events/TV tapings) for Wrestling/{{WWE}} in January 2007 in a male disguise as [[FakeNationality a masked Japanese wrestler]] named Sensai, defeating male wrestler Jamie Noble each time. However, because these were non-televised events, thus they were not part of any kind of continuity, and because Malawaski was released before ever appearing on WWE TV under any name, it qualifies as an aversion.
* In Wrestling/{{TNA}} Wrestling, the Latin American Xchange was often helped in their matches against the Rock 'n' Rave Infection by a mysterious Latino in baggy gangsta attire with a bandanna covering "his" face whom the LAX only referred to as "a member of the Latino nation". This mystery "man" often attacked the Infection's valet, Wrestling/ChristyHemme, prompting her to repeatedly complain to on-air authority figure Wrestling/JimCornette about the "man-on-woman violence" going on. Of course, the mystery member of LAX later revealed herself as a Latina named Salinas, thus trouncing the Rock 'n' Rave Infection claims.

[[folder:Tabletop Games]]
* ''TabletopGame/{{Ravenloft}}'':
** There's a series of supplements called the Gazetteers, which featured a scholar known as S who traveled around the major domains of the setting and chronicled their cultures. Everyone assumed S was a man until Gazetteer III, which featured a throwaway line about S's struggles to manage the layers of corsets, skirts, and petticoats that one domain expected its citizens to wear. Even then, some fans continued to insist that S was a man (apparently more willing to believe the character to be a drag queen than a woman), and it wasn't until an actual illustration of her appeared in Gazetteer IV that the argument was put to rest.
** [[SerialKiller The Midnight Slasher]] (an insane {{Expy}} of sorts of UsefulNotes/JackTheRipper) is assumed to be male, but is secretly a woman, driven insane after the murder of her parents at the hands of the domain lord of Invidia, Gabrielle Aderre. Most residents of Invidia assume the killer to be a man, never suspecting the disheveled beggar they see on the streets by day to be a cold-blooded killer by night; in fact, that's how she keeps the façade alive.
* In the ''TabletopGame/YuGiOh'' card game, there's [[http://yugioh.wikia.com/wiki/Gravekeeper%27s_Assailant Gravekeeper's Assailant.]] There was never anything to suggest that the monster on the card was female until she appeared on ''Anime/YuGiOhGX'' as a Duel Spirit, at which point it was obvious (even while still wearing the mask and cloak). The anime even gave her the name Sara (Yasmine in the dub version). (Of course, whether "Gravekeeper's Assailant" is a title that is unique to her is hard to tell.)
* In one of the vignettes in ''TabletopGame/{{GURPS}} Steam-Tech'', describing a new fad at {{Oxbridge}} for chivalric duelling with blunt swords (the relevant "tech" being applying 19th century metalsmithing to armour), a masked combatant who wins two out of three fights removes their helm to reveal "the well-known feminist agitator Miss Viola Dalrymple".

* ''Theatre/IntoTheWoods'': "[[spoiler:The Giant]]'s a woman!"
* The title character in Ben Jonson's ''Epicene'' is revealed at the end to be a boy disguised as a girl. In this case, the twist is only possible because [[CrosscastRole all female roles were played by boys]] at the time the play was written. (It isn't staged much today.)

[[folder:Video Games]]
* Toby Masuyo in ''VideoGame/{{Baraduke}}'' predates Samus by about a year (although the fact that the game calls her "Kissy" is a bit of a giveaway). Her next appearances in the ''VideoGame/MrDriller'' series and ''VideoGame/NamcoXCapcom'' do not play with this trope, opting to have her helmet-less (she's Mr. Driller's mom, after all). Ironically, Namco decided to officially name her "Toby Masuyo" -- thus giving her a GenderBlenderName long after TheReveal in her game of origin.
* The NES game ''VideoGame/MachRider'' had an arcade port where the eponymous character is seemingly revealed to be female after playing through enough levels. It might not be the case, as it could simply be {{Fanservice}} to the player, but if it were really the case it would mean that she predates Samus herself as Nintendo's first heroine.
* Inverted in ''VideoGame/DarkSouls'', where we have Gwyndolin, the youngest Child of Gwyn, Lord of Sunlight. Judging from his appearance and his title as "Goddess of the Darkmoon," you wouldn't think he was actually a guy. When he was young, he exhibited an affinity for moonlight magic, a trait considered feminine. Gwyn [[RaisedAsTheOppositeGender raised his son as a daughter]], having him wear a beautiful moonlight dress and even forcing him to wear a ring that would magically make him compose himself as a woman. The only indication that Gwyndolin is actually male is in a few item descriptions. The androgynous voice and lack of real dialogue directly from him concerning his gender leaves him perfectly passable as female, and the trope only kicks in if you read the item descriptions [[spoiler:or when [[VideoGame/DarkSoulsIII Yorshka]] mentions that Gwyndolin was her elder brother if you ranked high enough in Blade of the Darkmoon]].
* Zelda's disguise as the male Sheik in ''VideoGame/TheLegendOfZeldaOcarinaOfTime'', who was designed with a male character model to keep the disguise more convincing; the Water Sage Ruto actually referred to Sheik as male in the game. Programmers admitted she didn't get a more realistic design until ''[[VideoGame/SuperSmashBros Super Smash Bros. Brawl]]''. For some time, there was a very popular fan theory which stated that Sheik ''is'' male, and that Zelda not only changes appearance but also physical sex when she transforms. WordOfGod has since stated that this is not so; Zelda can't change her entire body like that, just a few surface details.
* In ''[[VideoGame/TheLegendOfZeldaSkywardSword Skyward Sword]]'', [[spoiler:the Master Sword is revealed to be female (Fi). Technically the Goddess Sword, but eventually our old friend.]]
* Syfa/Sypha from ''VideoGame/CastlevaniaIIIDraculasCurse''. Just to make sure the audience knows Sypha is a woman, in ''VideoGame/CastlevaniaJudgment'' she has very large breasts, and her breasts are even a joke in [[VideoGame/CastlevaniaRondoOfBlood Maria Renard's]] story. In addition, her ending confirms that she was [[SweetPollyOliver deliberately posing as a man]] in ''Castlevania III''.
* [[http://images4.wikia.nocookie.net/__cb20090322080212/castlevania/images/b/b2/SoTN_Old_Axe_Armor.JPG Here]] is the sprite for the playable Old Axe Armor from ''VideoGame/CastlevaniaPortraitOfRuin''. [[http://castlevania.wikia.com/wiki/File:Por_pic_41.jpg Here]] is an official piece of artwork of the same character.
* In ''VideoGame/KidIcarusUprising'', it turns out [[spoiler:''Dark Lord Gaol'' is one]]. It's been speculated that this was a deliberate nod to the {{Trope Namer|s}} herself.
* This is the twist in Akira's ending in ''VideoGame/RivalSchools: United By Fate''. The introduction of the story mode introduces her as the younger brother of gang leader Daigo Kazama and refers to her as male. The masquerade is carried on throughout the story, and even in her [[MultipleEndings "bad" ending]] -- only when you achieve the "good" ending is Akira's true identity is revealed.
** Akira is also playable without her helmet, as a secret character which you unlock after beating the game with the good ending (notably, in the usual slide show during the credits, she is seen helmetless with her Gedo schoolmates, but if the player didn't get the good ending, they'll probably be left clueless, as in "who's that girl? where's Akira?"). Which is interestingly inverted in ''Project Justice'': she starts off helmetless (due to ItWasHisSled), ''and'' her helmeted costume (labeled "Powered Akira") is the unlockable one.
* King in the first ''VideoGame/ArtOfFighting'' game nearly pulls this off despite [[{{Bifauxnen}} not wearing an actual disguise]]. By finishing her off with a special move in the last round, the player can [[ClothingDamage blow her shirt open and expose her bra.]] In the second game and ''VideoGame/TheKingOfFighters'' series, King's true gender [[ItWasHisSled is an already known fact]].
* [[{{Pirate}} Captain Syrup]] from the first ''VideoGame/WarioLand'' is a villainous example; the game's instruction manual even refers to her with masculine terms to avoid ruining the surprise.
* Faris of ''VideoGame/FinalFantasyV''. Although she seems to pass for male strictly because [[StupidityIsTheOnlyOption she says so]], as she's pretty enough for Bartz and Galuf (dueling Bobs) to swoon over her sleeping form, still thinking she's a he. This, of course, leads to Gilgamesh's classic line in the GBA Remake: "And now we will fight like men. And ladies. And ladies who dress like men."
* ''VideoGame/FinalFantasyTacticsA2'' plays with this in reverse. One of the recurring enemy characters is the Night Dancer, a Bangaa that looks, acts and is referred to as being a girl, but the fight against her has a Law in place forbidding harming the opposite sex, setting up a potential hazard for the player who does not understand the difference between gender and sex. Lampshaded by an NPC who is confused on what gender the Night Dancer is and another NPC refers to the character as an old man.
* This happens to Apollonia Vaar of ''VideoGame/GranblueFantasy'', under her occupation as the fully-armored Black Knight. While it's quite blatant from her voice and the in-game journal makes no attempt to hide her gender, the characters are a bit taken back when they see her without the armor. [[spoiler:With the exception of Eugen, who knew her identity, because she is his daughter]].
* This is the main twist in the ending of the iOS edition of ''VideoGame/DeadSpace''. [[spoiler:Vandal reveals her true identity to be Karrie Norton as she lies wounded on the floor near the defeated final boss.]]
* Happens ''twice'' in ''VideoGame/TalesOfVesperia''. The first is with Yuri's pursuit of "Mr. Mordio" -- which turns out to be a ''Rita'' Mordio; the second is with the mysterious (and kickass) DragonRider -- which turns out to be [[spoiler:Judith]]. In both cases, Yuri winds up the "Bob". And in both cases, they remain a full-fledged mage and warrior, respectively.
* Throughout ''VideoGame/TalesOfXillia'' and ''VideoGame/TalesOfXillia2'', the player is told about the Genesis Sage Kresnik, the first person to [[SummonMagic summon]] [[PhysicalGod Maxwell]] and who holds so much responsibility for the world's current state. Late in ''Xillia 2'' it's discovered that Kresnik's full name was Milla Kresnik, and Milla Maxwell was created in her image.
* ''VideoGame/MetalGearSolid'' does this with Meryl, who "disguises" herself as a male soldier, though it's really only because [[FacelessGoons all the uniforms look more or less exactly alike]].
* The Cyborg Ninja in ''VideoGame/{{Metal Gear Solid 2|SonsOfLiberty}}'' is not Gray Fox as in the first game, but instead [[spoiler:Olga Gurlukovich]].
* The last target in ''VideoGame/AssassinsCreedI'' is not there when you go to kill him. [[spoiler:The person disguised as him is revealed to be a woman after [[PlayerCharacter Altaïr]] defeats her in a swordfight. It's only somewhat given away in that when you hit her, her pained grunts are notably higher pitched than normal.]]
* In ''VideoGame/AssassinsCreedIVBlackFlag'', we're treated to James Kidd, the supposed illegitimate son of the captain William Kidd, who reveals to Edward (and the player) [[spoiler:her true identity as Mary Read, an assassin/pirate.]]
* The Power Armor in the ''VideoGame/{{Fallout}}'' series has always been gender neutral, but hearing a female voice from the Power Armor speakers in ''VideoGame/{{Fallout 3}}'' caused players spit-takes.
** Before then, ''most'' power-suited Enclave soldiers in ''VideoGame/{{Fallout 2}}'' were actually female. Even some that you spoke to.[[note]]Humorously, [[DrillSergeantNasty Sergeant Dornan]] is referred to by the interface as a "she", though that's more of a bug than this. Sergeant Dornan is very definitely male.[[/note]]
** ''VideoGame/FalloutNewVegas'' has two female Nightkin super mutants, Lily and Tabitha, who have the same guttural voice as the other mutants. In addition, female characters wearing full helmeted NCR Ranger/Riot Gear Armor or Reinforced Combat Armor are nearly indistinguishable from males.
** [[spoiler:The Mechanist]] in the DLC expansion ''Automatron'' for ''VideoGame/{{Fallout 4}}'', whose helmet contains a voice modulator to sound male. [[spoiler:She's actually a young and [[IntelligenceEqualsIsolation socially awkward]] WrenchWench named Isabel Cruz]].
*** It's not possible to tell if the [[EliteMooks power armored guards]] seen on board the ''[[CoolAirship Prydwen]]'' or encountered on patrols throughout the Commonwealth are male or female until they speak to you. Like in ''Fallout 3'', it can be a bit of a surprise sometimes to hear a female voice coming out of the [[RageHelm helmet's]] speakers.
** In contrast to the exclusively male PowerArmor Enclave Soldiers in ''Fallout 3'', the ''New Vegas'' mod ''For the Enclave'' seems to have more female soldiers in armor than male. Most of them also [[WelcomeToCorneria repeatedly claim that General Jamison will lead them to glory, almost as often as NCR Troopers will complain about how patrolling the Mojave almost makes them wish for a nuclear winter.]]
%%** Fawkes was never intended by the game designers to be male. It was a mistaken assumption by Wes Johnson. In any case, observe the seam lines on the tattered remnants of his vault suit; they match the men's vault suit, not the women's. Do not reinstate Fawkes as an example, because he is not.
* In ''VideoGame/HotTinRoofTheCatThatWoreAFedora'', we are served a double dose of this trope. Private Inspector Jones is respected and well-established in the police force, and depending on your dialog choices, you can go quite a long way before someone call ''her'' by full name, "Emma Jones." Her figure being little more than a blocky [[FedoraOfAsskicking badass fedora]] over a blocky [[BadassLongcoat trenchcoat]] doesn't exactly help in identifying her gender, especially if you have met her girlfriend before the reveal. Special mention for weasely dialog writing as her girlfriend calls her "Em," which can look like she's simply hesitating when speaking. The second serving of this trope is delivered shortly after, when talking with your sidekick, the cat Frankie. While you had previously the chance to learn that Frankie is [[TokenMinority the only cat to have made it into the police force ever]], you probably did not suspect that "Frankie" was short for "Francine."
* [[spoiler:Naoto Shirogane]] in ''VideoGame/{{Persona 4}}''. With the twist that the party finds out when they show up to rescue ''her'', rather than her rescuing them. Unfortunately this was completely spoilered by the dub--in the Japanese version her being voiced by a woman was hardly unusual (a lot of young men and boys are voiced by women in anime and games), but in English her gender is completely unmistakable, ruining the surprise.
* ''VideoGame/{{Portal}}'' plays with this, in that the [[HeroicMime main character]] is female, but there's no indication of this until you happen to get a good look at yourself through a portal. While you can clearly see yourself in the very first portal you step through, it's hard to tell that it's you right away. Averted in ''VideoGame/{{Portal 2}}'', in which Wheatley refers to you as female from the very start. However, ''Portal 2'' has an in-universe example where Wheatley passively assumes that whoever beat [[MasterComputer GLaDOS]] was a guy, and is taken aback when he finds out that it was ''you''.
* The first ''VideoGame/DestroyAllHumans'' revealed that Majestic-12 leader Sillouette is a female at the end, though you can learn this earlier on if you read the thoughts of a Magestic agent, which you might just ignore.
* WordOfGod states that this was to have been the big reveal at the end of the fifth game in the old UsefulNotes/ZXSpectrum Magic Knight series (''Finders Keepers'', ''Spellbound'', ''Knight Tyme'', ''Stormbringer'' and...). Possibly OlderThanTheNes, possibly not (the first two games both came out in 1985, and the first game definitely refers to Magic Knight as 'he', so it may not have been planned at that point).
* In the first ''VideoGame/{{Tekken}}'', Kunimitsu was simply a palette swap of Yoshimitsu, with the same voice as well. In the second game, the character was revealed to be female. Although it has to be said, she was always meant to be female, as you can see in concept art. [[ViewerGenderConfusion 3D graphics weren't that good]] at the time of the first ''Tekken'', however.
* Leo from ''Tekken 6'' is widely believed to be a woman dressed as a man, or a gay male. Namco have deliberately not confirmed either way, stating they wanted to create a character who could be "loved by either gender." [[spoiler:She was later confirmed to be female by WordOfGod prior to the release of ''Tekken Tag Tournament 2''.]]
* In the game by Tim Schafer, ''VideoGame/BrutalLegend'', Eddie, the main character, fights many demonic druid enemies in robes, and then faces one of them head on. In the middle of the fight, that "evil druid" flips off her hood to reveal that this is, in fact, a female human. Eddie then remarks, "Oh no, don't tell me I've been slaying hot girls this whole time."
* At the end of ''VideoGame/DragonQuestMonsters'', the [[spoiler:masked monster master at the Starry Night tournament is revealed to be Milayou, the protagonist's younger sister.]]
* Hooktail, the boss of the first level in ''VideoGame/PaperMarioTheThousandYearDoor'', is assumed to be male by all characters (and described with male pronouns in Goombella's Tattle), until the final chapter, when you meet Gloomtail in the Palace of Shadow. When your partner asks what Hooktail is doing here when you've already beaten him (as Gloomtail is essentially a palette swap of Hooktail), Gloomtail becomes furious upon learning what you did to his precious baby ''sister''. Tattling on Gloomtail elicits a hilariously shocked reaction to this revelation from Goombella.
* ''VideoGame/Sly3HonorAmongThieves'' gives us [[spoiler:the Black Baron, an ace fighter pilot whose face is entirely covered by his huge mustache. Only after you beat him do you learn that he's actually GadgeteerGenius Penelope, who created the disguise to get around the dogfighting league's age restrictions. Happens again in ''VideoGame/SlyCooperThievesInTime'', where the Black Knight is revealed to be Penelope again, this time signifying her FaceHeelTurn.]]
* The mysterious scrambled voice in the marine campaign in ''VideoGame/AliensVsPredator 2'', though she never actually does any fighting.
* Black Widow from ''[[VideoGame/SaturdayNightSlamMasters Ring of Destruction: Slam Masters II]]'', is a somewhat effeminate wrestler who is taller than most of the other wrestlers in the game and whose spider-themed costume covers his whole body. If you beat the game with him, Widow reveals herself to be a [[StatuesqueStunner tall]] and [[AmazonianBeauty muscled]] female wrestler.
* Around half-way through ''VideoGame/RatchetAndClankGoingCommando'', the thief you have been pursuing is unmasked to reveal that she is female, to Ratchet's surprise. This also marks the point at which she stops being an enemy, but more because [[EnemyMine they were betrayed by the real villain]].
* Junon from ''[[VideoGame/DragonForceSega Dragon Force]]'' pulls this one on everyone in her world until her helmet gets knocked off during an encounter. [[http://img525.imageshack.us/img525/7150/thedragonforcepe0.png She's the one in the badass black armor.]] [[http://img221.imageshack.us/img221/1096/gatheringtotallabelledwb5.png She's also #139.]]
%%* [[spoiler:The Great Mizuti]] from ''VideoGame/BatenKaitos''.
* The video game series ''VideoGame/GuiltyGear'' is notorious for pulling off a reverse of SIAG (Bridget needs no introduction), but what many people don't know is that WordOfGod has stated that Justice, the final boss of the first game, the Commander Gear, a large, powerful robot-type person with a noticeable crotch spike, is really a female and was a dear friend of Sol Badguy's. [[spoiler:In fact, ''Xrd -REVELATOR-'' openly reveals her to be, as implied throughout the previous games, his old lover from back when they were human.]]
** In regards to the infamous crotch spike, it's possible that the protrusion on her armor is Justice's equivalent of an [[https://en.wikipedia.org/wiki/Ovipositor ovipositor;]] [[ShownTheirWork after all, she is the queen bee/queen ant of the Gears.]] [[spoiler:The fact that Dizzy, Justice's daughter, gives birth to her son Sin by ''[[BizarreAlienBiology laying an egg]]'' (as recounted in the ''[[AllThereInTheManual Guilty Gear 10th Memorial Book]]'') seems to support this assumption.]]
* ''Franchise/DragonAge'':
** [[spoiler:Shale]] from ''VideoGame/DragonAgeOrigins'' is [[spoiler:a amnesiac golem who has a masculine personality and build. However, if you have Shale in your party during the "A Paragon of Her Kind" quest, it is revealed that Shale was once a dwarven woman named Shayle. Even Shale herself is stunned by this revelation.]] Her voice is obviously female, she has an obsession with "pretty pretty gemstones," and if you keep them both in the party she flirts with Sten constantly.
** In the [[{{Worldbuilding}} universe backstory]], there is a tale of an [[UsefulNotes/{{France}} Orle]][[FantasyCounterpartCulture sian]] woman named Aveline, who dared to compete in a knight's tournament, hiding her identity behind a helmet even when it was ill-suited to a particular game. She matched a rather arrogant knight favored by the emperor, fighting to a standstill in a duel when a chance blow sent her to the ground and knocked her helmet off. The haughty knight tried to have the match declared invalid because of her womanhood, to which the crowd responded with a hefty amount of jeering. The knight responded by killing her as she lay helpless. The at-the-time emperor's son, who also was bested by the very same woman in the tournament, was taken aback, and he abolished the laws prohibiting women to become knights in Orlais when he ascended to the throne and posthumously knighted her. Aveline Vallen in the [[VideoGame/DragonAgeII second game]] was named in honor of this knight.
** Also in the backstory, [[TheMagocracy the ancient Tevinter Imperium]] worshipped seven Old Gods in the form of dragons. All seven were assumed to be male, but in the ''Jaws of Hakkon'' DLC for ''VideoGame/DragonAgeInquisition'', the player finds a temple devoted to the Old God Razikale, the Dragon of Mystery. Inscriptions found in the temple refer to Razikale with female pronouns.
* In ''VideoGame/MirrorsEdge'', Faith spends part of the game chasing after [[spoiler:an assassin - who is also a runner like herself - who Faith assumes to be male]]. Much later, when Faith gets into combat with [[spoiler:the assassin]], it is revealed that [[spoiler:it is none other than her treacherous best friend, Celeste]].
* Chris from ''VisualNovel/PrincessWaltz'' is taken to be a man by the main character. Even despite many hints and on multiply occasions fusioning together to become a woman, the main character doesn't realize that Chris is actually a girl until... well... Either way even the main character feels stupid for not getting the hint before.
* The sequel to ''VideoGame/CrystalQuest'' reveals your FlyingSaucer -- depicted in gameplay as a 16-pixel-wide circle -- to be piloted by a ''[[VertebrateWithExtraLimbs six-legged]] [[SpaceX Space]] [[EverythingsBetterWithCows Cow]]'' (who is, of course, a girl).
* [[spoiler:Monica]] from ''VideoGame/DarkCloud 2'' first appears disguised as a young child when you first meet her, and after [[spoiler:she defeats the MonsterClown who was trying to seize Max's MacGuffin]], removes her [[InTheHood hood]] and reveals herself to be a woman.
* [[spoiler:Alexis]] of ''VideoGame/ValkyriaChroniclesII''. Her voice kinda gives her away, quite a few players were still confused by the fact the game's encyclopedia classifies her as male, and that she has a male character model in game.
* Julian from ''VideoGame/{{Growlanser}}''. Her portrait is a giveaway when you first meet her as an Imperial Knight (you can see she has cleavage if you closely examine the portrait where she holds her sword). It was stated that Imperial Knights does not allow females to join, thus she hid her gender (though her two fellow companions Oscar and Lyell already found out and choose to ignore it).
* Jayle from ''VideoGame/ValkyrieProfile''. A noblewoman JeanneDArchetype who disguises herself as a man in order to join Gerabellum's order of knights. Only her commanding officer knows of her disguise but says nothing about it, as he's [[SweetOnPollyOliver fallen for her]].
* In ''VideoGame/{{Disgaea 2|CursedMemories}}'', everybody assumed Overlord Zenon is a male, but turns out [[spoiler:Rozalin was the reincarnated Zenon]], though [[spoiler:the game's "reincarnation" mechanic allows non plot characters to reincarnate into any class, even opposite sex ones. And technically, we don't actually know what Zenon's original gender was]]. Note that [[spoiler:Rozalin]] is very clearly female, so this is more of a case of [[InvertedTrope The Girl is Samus]].
* Subverted in ''VideoGame/{{Hydorah}}''. Throughout the game, the player character is conspicuously helmeted, but is revealed in [[AllThereInTheManual official artwork]] to be [[spoiler:male]].
* ''VideoGame/DragonFable'' has Vilmor. She was assumed to been a male not only by the PC, but also by a majority of the players, despite obvious hints early on into her storyline. Was even referred to as male in a [[AllThereInTheManual Newsletter]].
* In ''VideoGame/{{Faria}}'', the player character is only called by a [[HelloInsertNameHere player-given name]] and represented by an androgynous SuperDeformed sprite, and the gender is not revealed until the king explains that he can't give her the StandardHeroReward for having saved the princess ([[spoiler:the fake one, that is]]). [[spoiler:However, it turns out he's really a handsome prince under a curse.]]
* In ''VideoGame/FireEmblemAwakening'', there's a masked swordsman/AntiHero who shows up early in the game, claiming to be the legendary Hero-King Marth. [[VideoGame/SuperSmashBros Previous incarnations of]] [[VideoGame/FireEmblemAkaneia that character]] have been, while [[{{Bishonen}} somewhat androgynous]], definitely male... but it turns out "Marth" is a woman. Specifically, she is actually [[spoiler:[[LadyOfWar Lucina]], [[TheHero Chrom]]'s [[KidFromTheFuture time-traveling daughter]]]].
* The otherwise {{featureless|Protagonist}} detective in the PC HiddenObjectGame series ''VideoGame/MysteryCaseFiles'' is revealed to be this. Her very feminine voice is heard on the telephone at the end of the second game of the Ravenhearst arc. However, later in the series a new dev team made it more ambiguous, giving the player the choice of whether to have a male or female character. Later still, when Eipix Entertainment took over the series, the Master Detective went back to female.
* The detective in ''VideoGame/DarkParables'' has her gender confirmed by unlockable BonusMaterial in the collector's edition of the first game. This makes sense, as there is almost no character interaction in this game which could have revealed the detective's gender. Later in the series, other characters refer to her using female pronouns.
* ''VideoGame/{{Okami}}'' had this happen with Amaterasu, as some referred to Ammy as a male while others referred to Ammy as a female, leading to fans to argue among themselves over it. A known fact, however, is that Deities can have whatever gender they please, and the Amaterasu of Shinto was originally female... But this one is the reincarnated Shiranui, who was male... What's the truth? It was never known until...
* ''VideoGame/{{Okamiden}}'' revealed Amaterasu's true gender! [[spoiler:Ammy is female, Shiranui is male and they are related family-wise! Shiranui is Amaterasu's father and Chibiterasu's grandfather, where Chibiterasu is Amaterasu's son and they say Ammy is his MOTHER.]] Until this reveal happened, the arguments in favor of Ammy being male boiled down to Ammy leg lifting up their leg when using Golden Fury. Except dog owners would contradict that by knowing both male AND female dogs lift their leg when marking territories, so it was often deemed flawed evidence.
* In ''VideoGame/JaysJourney'', [[spoiler:Shade. Not only did everyone think Shade (aka Tanya) was male, Atolla believed Shade was Tanya's brother Tezla, and a series of flashbacks implied the same conclusion until the last one.]]
* In ''VideoGame/RhythmThiefAndTheEmperorsTreasure'', Charlie/Claude is the inspector's son and basically a thorn in Phantom R's side... [[spoiler:but as it turns out, that person is the inspector's ''daughter'' named Charlotte]].
* Though not explicitly stated in-game, the player character from the Protoss segment of ''VideoGame/{{StarCraft|I}}: Brood War'' was revealed to be Selendis, a female Protoss executor.
* During ''VideoGame/MightyNo9''[='=]s Webiste/{{Kickstarter}} campaign, when discussing [[https://www.kickstarter.com/projects/mightyno9/mighty-no-9/posts/607055 Mighty No. 8,]] the developers revealed that they initially planned to have TwoGirlsToATeam regarding the Mighty Numbers themselves, so director Koji Imaeda requested No. 8 to be a girl. The resulting preliminary sketch the lead character designer Kimo Kimo created for No. 8 was of a man, since he felt it matched the character's theme (radar and optical camouflage) better. The project leader, Creator/KeijiInafune, liked the design, so it appeared that [[https://www.kickstarter.com/projects/mightyno9/mighty-no-9/posts/600219 Mighty No. 3]] was subjected to TheSmurfettePrinciple... until a later update long after the Kickstarer campaign revealed that Kimo Kimo made [[https://www.kickstarter.com/projects/mightyno9/mighty-no-9/posts/906839 Mighty No. 2]] a girl as well, since he found No. 2's theme (water and ice) a better fit for the gender. Of course, the finalized version of No. 2's character design was one of the first things presented in the Kickstarter campaign, and since it was essentially a baby in an old-fashioned diving suit, it was impossible to determine her gender from appearances alone.
* ''VideoGame/ProfessorLaytonVsPhoenixWrightAceAttorney'':
** One puzzle is a riddle about a king who has been attacked, and you must find the culprit from one of five people in the room using their testimony. The prince will say he heard a woman's voice, but he arrived before the princess and villager, the only two characters that are visibly female. This means that [[spoiler:the culprit was the knight, who is actually a woman under the armor]].
** The no-nonsense, intelligent, and to-the-point Jean Greyerl is actually a girl, masquerading as a boy to avoid accusations of being a witch.
* Ghost from ''Raze 3'' sounds like a boy at first; later, after saving the main protagonist from the Alien Leader, she's revealed to be a girl after taking the mask off.
* Several documents in ''VideoGame/ResidentEvil5'' reference Alex Wesker, which fans deduced from the unisex name and total lack of gender-specific pronouns that the new character was most likely going to be a woman. The Japanese version ''did'' use masculine pronouns to refer to Alex, making it seem like this was just an accidental quirk in the English translation and Alex Wesker was really a dude. As of ''[[VideoGame/ResidentEvilRevelations2 Revelations 2]]'', it turns out [[spoiler:the fans were right all along; Alex Wesker is female!]]
* At the end of the Imperial Agent's storyline in ''VideoGame/StarWarsTheOldRepublic'', [[spoiler:[[TheRival Hunter]]]] is revealed to be a woman using a holographic disguise to pose as a man, having discarded her original identity long ago.
* Averted in ''VideoGame/{{Undertale}}''. While you first see Undyne wearing huge feature-obscuring armour, she is explicitly referred to as a woman before you even see her for the first time. There's also Knight Knight, whose gender you wouldn't be able to determine if not for the flavor text.
* ''VideoGame/TeamFortress2'': Due to Pyro wearing a feature-obscuring suit and mask, a lot of fans suspect this of them, and it's led to a lot of debate on all sides. [[Creator/ValveSoftware Valve]], very much aware of this, decided to settle the debate in true TrollingCreator fashion in the supplementary comic "Old Wounds": [[spoiler:There ''is'' a female Pyro, but it's the ''VideoGame/TeamFortressClassic'' Pyro, who was always portrayed with a masculine body and voice. (Her name is Bea, for the curious, short for Beatrice.) The current game's Pyro's gender is still up for debate, partially because Valve finds the speculation more funny and interesting than actually settling the debate.]]
* Played with in ''VideoGame/QueenAtArms''. The player is perfectly aware almost from the beginning that Marcus Cordale is secretly a woman, hiding her identity. But everyone else in the game, except for her brother Nick, believes her to be a man. Depending on which story path is followed, TheReveal is presented to various other characters in very different ways. For the player, and Marcus herself, the twist is not her true gender but the reason ''why'' she has to hide it.
* In ''VideoGame/FossilFighters Frontier,'' it's revealed that T-rex, the MascotMook of the franchise, is female... or at least, the iconic version of her is. The classic red-and-black [[DinosaursAreDragons Fire-type]] T-rex seen in previous installments of the franchise is the female version, called [[GeniusBonus T-rex Sue]]. The game introduces a male version named [[FluffyTheTerrible T-rex Stan]], who is Air-type instead.
* In ''VideoGame/MassEffect2'', "The Convict" is known only as "Jack," a psychotic mass-murderer with extremely intense biotic powers. Throughout the recruitment mission, Jack is referenced as a terrifying individual, but never referred to with male or female pronouns. Shepard is surprised, upon releasing Jack, to discover that Jack is a woman. This reveal was spoiled both in the [[TrailersAlwaysSpoil advertising]] and the demo for the game.
* In the ending cutscene of ''Avenger'' for the UsefulNotes/PCEngine, the helicopter's pilot finally removes ''her'' helmet.
* In the relatively new Flash, in-browser game ''VideoGame/RPGShooterStarwish'', Mare is a character who is shown and (repeatedly) told of being a much better pilot and shooter than the protagonist of the game as while as having "a very deep, modulated voice". Late in the game Mare takes off her robot-like suit to reveal that she [[spoiler:is one of the three remaining survivors of Lucerna]].
* Lampshaded in ''VideoGame/{{Grandia}}'' where one of the protagonists is initially introduced while she is off-screen as simply the best adventurer in the adventurers' society. Cue Justin imagining him as a large burly man with many scars before meeting her and realizing she is in fact female.
* In the main series ''Franchise/{{Pokemon}}'' games, the assignment of genders for Pokémon have been a part of the series' gameplay mechanics starting with Generation II's ''[[VideoGame/PokemonGoldAndSilver Gold and Silver]]''. Since then, members of certain species can be either gender, designated to be [[OneGenderRace only one gender]], or genderless. Transferring a Pokémon that could be either gender from Gen I to Gen II would finally reveal whether it's male or female. Players can experience these reveals again, because the Gen I games have been released on the 3DS UsefulNotes/VirtualConsole. Later on, they can transfer Pokémon with unknown genders from those games to ''[[VideoGame/PokemonSunAndMoon Sun and Moon]]''.
* In ''VideoGame/SouthParkTheStickOfTruth'', the player can only play as a boy, but in ''[[VideoGame/SouthParkTheFracturedButWhole The Fractured but Whole]]'', which is explicitly a direct sequel starring the same character, the player can choose their gender. This is done via Mr. Mackey giving you TheTalk and asking for your gender. If the player identifies as anything other than a cis male, he's utterly baffled and calls up your parents to confirm that you were in-fact not a boy the whole time while lampshading this as explicit {{retcon}}ning. This is explained as your parents wanting to keep your identity a secret from the government and Wendy reveals that she knew that you were not a boy since the first game, but kept it secret out of respect for what she believes to be your desire to be mysterious.
* ''VideoGame/BatmanTheTelltaleSeries'' sees the Children of Arkham's leader turn out to be [[spoiler:[[AdaptationalVillainy Vicki Vale]]]].
* ''VideoGame/MassEffectAndromeda'' invokes this. The salarian ark Parcherro is captured by [[spoiler:or rather, sold out to]], the kett. Captain Hayjer theorizes correctly that their pathfinder, the female Zevin Raeka, would be in serious danger if caught, so he engineers a FakingTheDead plot. He uses the body of a male salarian who died when the kett took the ship and puts his body in Raeka's pod. The plan operates on the belief that, since the kett have no experience with salarians, they would be fooled by this trick, but any rescuers from the Milky Way would know the difference between male and female salarians, and easily see through the trick.
* ''VideoGame/ForzaMotorsport 7'' reveals that M. Rossi, the series' top AI driver, is female and her first name is Maria.
* The Adventurer from ''VideoGame/BravelyDefault''. The mysterious red-cloaked figure serving as a Save Point, item store, and BonusBoss throughout the franchise shows up in the sequel's finale to save the day, revealing herself to be a woman and [[spoiler: a Celestial Being capable of traveling through time and space]].
* In ''VideoGame/{{Shenmue}}'', Master Chen refers to [[spoiler:Lishao Tao]] as one of Hong Kong's elder martial art masters. When Ryo does finally meet the character in ''VideoGame/ShenmueII'', "he" turns out to be a beautiful young woman in her mid-twenties.
* In ''VideoGame/TheLegendOfDragoon'', the "Black Monster" who murders Moon Children and any innocents in their way every OneHundredAndEight years is referred to either with masculine or neuter pronouns. Later in the game this "Monster" is revealed to be a female party member who you first met not even ten minutes into the game (and becomes your fourth recruited party member). This is further amplified in the [[GhostShip Phantom Ship]] where the Monster is referred to with masculine pronouns a lot by Dart (the protagonist) and the ghosts onboard, while the Black Monster herself tags along the entire time.

[[folder:Visual Novels]]
* Inverted in ''VisualNovel/FateStayNight''. LadyOfWar Saber is obviously a female knight, but it isn't until later on that we learn she is actually [[spoiler:the legendary KingArthur]], who used magic to disguise herself as a man because [[spoiler:[[TheWomanWearingTheQueenlyMask she felt that the British probably wouldn't obey a Queen]].]]
** ''RolePlay/FateNuovoGuerra'' follows tradition and chocks one up with a certain Lancer from UsefulNotes/TheTrojanWar, though it wasn't so much a disguise as it was "[[PoliticallyCorrectHistory sexist historians]]" who didn't like how a girl was getting all that booty and kicking all that ass.
** The ''Fate'' series tend to do this quite a bit with some of the historical/mythical figures, most likely due the overwhelming success of Saber. Ironically, Nasu initially cringed at the idea of turning Saber into a female.
** The spinoff novel [[LightNovel/FateApocrypha Fate/Apocrypha]] also reveals [[spoiler:Mordred]] to be female.
* ''Franchise/AceAttorney'':
** ''[[VisualNovel/PhoenixWrightAceAttorney Justice for All]]'': Phoenix doesn't learn Manfred von Karma's child's gender until facing her in court. Later on in the same game, [[spoiler:Shelley de Killer incorrectly guesses that [[GenderBlenderName Adrian Andrews]] is a man, thus proving that he's never met her in person.]] Strangely, Phoenix refers to Engarde's manager correctly as a "she" during the initial interview, despite having no information on his manager beyond her existence. This was most likely due to the manager's name being very gender ambiguous, which plays a key role in the case and was something the writers intended.
** In ''[[VisualNovel/PhoenixWrightAceAttorneySpiritOfJustice Spirit of Justice]]'', [[spoiler: Armie Buff is a shut-in who could only communicate with an armed drone. She acts as a war general and talks in a scruffy masculine voice thanks to a voice filter. Naturally, when Armie revealed herself everyone in the courtroom is surprised to see the witness was a 12-year-old girl in a wheelchair.]] It's also [[InvertedTrope Inverted]] with [[spoiler: the vigilante rebel hunter styling themselves after the legendary Khura'inese female warrior Lady Kee'ra, who turns out to be a man.]]
* ''VisualNovel/DanganRonpa'' has this ''twice'': In Chapter 2, [[spoiler:the mysterious Genocider Syo, who has been referred to as "he" is revealed to be Touko Fukawa, a female student.]] Made even more shocking in the English release, where [[spoiler:"he" was named Genocider Jack before TheReveal, and Genocider ''Jill'' afterwards.]] Then in the final trial, it is revealed that [[spoiler:the person behind Monokuma is Junko Enoshima]]. This is the same for ''VisualNovel/SuperDanganRonpa2'', only this time [[spoiler:it is an AI version of her]].
* ''VisualNovel/FleuretBlanc'' has Augustine Hatch Jr., FOIL's mechanic and electrician. [[OnlyKnownByTheirNickname She is initially referred to as "Junior"]], and she only interacts with Florentine through a remote speaker for most of the story. Both the name and profession are coded male so Florentine assumes Junior is a man, leading to shock when Augustine shows up in person. This is also {{deconstructed}} a little: her father wanted a son, not a daughter, and named her "Junior" before she was even born in the hopes she would continue the family line. When he discovered his offspring was a girl, he was livid. The resulting neglect and disappointment likely skewed her psychological development and perception of gender roles in an unhealthy way, and may have influenced her decision to enter such a male-coded field in the first place. However, this is also {{reconstructed}} in that her father learned to love her anyway.
* ''VisualNovel/CodeRealize'' does this verbally. During Cardia's second confrontation with the Assailant in heavy armor, she's shocked to hear a woman's voice come underneath the armor. Her profile in the glossary notes that her name is [[spoiler:Guinevere (yes, ''[[Myth/KingArthur that]]'' Guinevere)]] and she is very beautiful. When we see her face later, we learn that her profile wasn't kidding.
* ''VisualNovel/{{Sunrider}}'' has a villainous example with [[BigBad Veniczar]] [[GalacticConqueror Arcadius]]. Most of the galaxy assumes her to be male, between her androgynous figure, masculine clothing, and wearing a face-concealing mask that also alters her voice. It isn’t until the very end of the first game that she’s unmasked as a woman, though her gender ends up being the ''least'' surprising aspect of that revelation. As for why she does this, the sequel reveals that [[spoiler:the original Arcadius ''was'' a man, and the current Arcadius has been impersonating him ever since his death]].

[[folder:Web Animation]]
* ''Machinima/RedVsBlue'':
** Agent Texas is a bit of a subversion of the usual way this trope is carried out. She's outed as female a few episodes after her debut when her helmet's voice modulator shorts out, but since everyone in the series is always wearing PowerArmor (because it's a ''Franchise/{{Halo}}''-based {{machinima}}), Tex is otherwise indistinguishable from the rest of the cast.
** Zigzagged with the former Agent Connecticut. When first encountered in Season 7, CT appears male in all respects, which confuses the hell out of the other Freelancers - flashback episodes in Season 9 show that the CT they knew was a woman. Then Season 10 reveals that [[spoiler:the original CT was killed, and her boyfriend took up her armor to honor her.]]
* [[spoiler:Spriggs]] in the ''Franchise/{{Halo}}'' {{machinima}} series ''Spriggs''.

[[folder:Web Comics]]
* Miko Miyazaki from ''Webcomic/TheOrderOfTheStick'' does this. For about eighty or so strips, she appears only as a blue-hooded figure, until she takes on the Order of the Stick, at which point she drops her hood and we see that yes, she is in fact female (and, [[InformedAttractiveness judging from Roy's reaction]], fairly attractive). Roy plays her Bob for a while, until he gets put off by her [[LawfulStupid personality]]. This wasn't that drastic, as she seemed more ambiguous than masculine prior to this -- insofar as she even seemed human at all.
* Also initially appearing as a hooded figure was [[spoiler:the previous Wotch]], Miranda West of ''Webcomic/TheWotch''. Her initial appearance was in the very first story arc. Her reveal was at the end of the ''fifteenth''.
* [[spoiler:Ashido]] from ''Webcomic/{{Inhuman}}'' is shown to be an example of this when another character walks in on her changing.
* [[EveryoneCallsHimBarkeep Peregrine Mendicant]] of ''Webcomic/{{Homestuck}}''. The [[WordOfGod author]] never intended her to actually have a gender at all, but [[AscendedFanon gave in to fan speculation]].
* ''Webcomic/{{Jix}}'':
** Pratos the Bounty ends up being both a female Ambis named Aranis and Jix's cousin. A possible nod to Samus Aran.
** Jix was thought to be male until her brother Romulos revealed her true identity (it's hard to tell what gender a small furry alien is unless you are able to see anything).
* ''Webcomic/AModestDestiny'':
** [[spoiler:Shadow]] spends a good amount of time in the comics as this until an incident where Maxim [[ThanksForTheMammaries grabbed her]] [[http://www.squidi.net/comic/amd/view.php?ep=1=100 breast]], and it's not shown who she is until much later.
** When the previously killed [[TheAce Crimson Blade]] shows up at [[FluffyTheTerrible the Vampire Lord Fluffy's]] castle, Fluffy's bat familiar flies of with the helmet, revealing that the new Crimson Blade is a girl. Expecting this trope, Fluffy immediately tries to hit on her, but actualy fails miserably.
* [[http://www.interrobangstudios.com/potluck/index.php?strip_id=1084 This]] [[Webcomic/EnsignSueMustDie Interrobang]] [[Webcomic/TriggerStar Studios]] comic where [[SuperMarioBros Luigi]] complains to Link about some gay Bounty Hunter in Orange armor who asked him out.
* ''Webcomic/GunnerkriggCourt'': The [[SomethingCompletelyDifferent interim comic]] ''City Face 2'' introduces a magpie named Bobeyes. In a bit of PaintingTheMedium, the ShoutBox below the comic features [[http://gunnerkrigg.wikia.com/wiki/City_Face_2_comments commentary by in-universe characters]]--one of whom is a magpie going by the username "magpie55". He thinks Bobeyes is a pretty cool, tough guy, and is as surprised as anyone to learn that Bobeyes is a girl. From his commentary on the final comic page, it's obvious that he's smitten.
* {{Inverted}} in ''Webcomic/HannaIsNotABoysName'''s [[http://hanna.aftertorque.com/?p=4 first]] [[http://hanna.aftertorque.com/?p=5 two]] strips, as [[FirstPersonPeripheralNarrator Zombie]] naturally assumed that "[[GenderBlenderName Hanna Cross]]" would be a woman. Played straight [[http://hanna.aftertorque.com/?p=23 a short time later]] when [[InvoluntaryTransformation bat!]][[FullyEmbracedFiend Adelaide]] was introduced.
* [[spoiler: Count Repugsive]] in ''Webcomic/{{Nodwick}}''. The reason she gives for the deception is that "female villains only get respect if they're hot". [[spoiler: Which she certainly isn't, being an undead BlackKnight.]]
* This is explicitly referenced in ''Webcomic/GirlGenius'', when one of the protagonists puts on a very Samus-like suit. This follows:
-->'''Agatha:''' No, I can't even tell you're girl.
* Played with in ''Webcomic/{{Pacificators}}''. On one side, [[TheStoic Taffe]] [[BlowYouAway Torbern]] doesn't ''actively'' dresses in a manner that would cause confusion about her gender, but she ''is'' flat-chested, and a tomboy. There have had been multiple instances in which she gets [[CrowningMomentOfFunny mistaken for a boy,]] especially by the TooDumbToLive pirate Ferdinand. In fact, when she was first introduced, the ''readers'' weren't sure whether she was a girl or a boy. It wasn't until the first encounter with the pirate Ferdinand that her gender is cleared up.
* ''Webcomic/WhenSheWasBad'' has a highly feared mob enforcer who goes by the name Coyote. Most people assume the Coyote is male, but she is actually a PerkyFemaleMinion named Rosie. Her employers are pretty much the only ones who know her true identity, since she never leaves witnesses alive.
* ''Webcomic/{{Visseria}}'' has Alchione, who until pointed out by a child, was unapparent to the reader as being female for the first couple of pages that she appeared. This was caused in large part by her armor, but also by her abnormal height and musculature.
%%* Done [[http://cockeyed.webcomic.ws/comics/122 here]] with a ninja-type figure in ''Webcomic/{{Cockeyed Comix}}''.
* In ''Webcomic/TowerOfGod'' Hwa Ryun kicked major ass before Baam broke her mask. And cut her eye.
* ''Webcomic/DarthsAndDroids'' has the revelation [[spoiler: "No, Luke, I am your ''mother''."]]
* In ''Webcomic/PrincessPrincess'', Sadie initially thinks that Amira is yet another prince come to rescue her. Amira tells her that she is no prince, she is a princess! And she has a grappling hook!
* In the webcomic ''Webcomic/DoesNotPlayWellWithOthers'', only the reader finds out that the arch-nemesis of the superhero Falchion is actually a woman. [[DatingCatwoman She ends up becoming Falchion's girlfriend]].
-->'''Janis:''' If someone catches you in the hideout without the armor on, pretend to be [[MadScientistsBeautifulDaughter the evil villain's confused daughter]] who just needs some [[AllWomenAreLustful lawful hot dickings]] to set her on the path to straight and narrow. Yeah, totally the best plan I ever made!
* ''Webcomic/YoungerDays'': the character Sam is easily mistaken for a boy, both in-universe and by readers, due to her having a [[GenderBlenderName gender neutral name]], boyish short hair, and hardly ever dressing in typical girl clothes.
* According to ''Webcomic/ItSucksToBeWeegie'', Luigi is oblivious to the TropeNamer. When Samus, the only girl who is into him, tried to pick Luigi up at a bar. Luigi, naturally, assumed she was a guy and said that he "doesn't swing that way". Cue Link giving a FacePalm and immediately offering Luigi afterwards to cry on his couch to sleep over "nothing".
* Dante of ''Webcomic/CharCole'' is a female Cubone, but since Cubones are a Pokémon species without visible sexual dimorphism, her trainer, Brian, did not realize this until he was informed of Dante's sex by Pokémon Center staff weeks after first catching her. Until Dante's gender was revealed, Brian's entire Pokemon Team (who were just as clueless as their trainer) considered her a boy, something that Dante is quite offended about once she learns it.

[[folder:Web Original]]
* ''Roleplay/DinoAttackRPG'':
** Played with; Agent Pyro spent the majority of the RPG wearing a gas mask, balaclava, and baggy pants, leading to some joking about his true gender. When it came time for the mask to come off, it turned out to be a woman to the shock of everyone. It's actually a subversion. Later on a psychotic, disheveled, and all-around unpleasant man started shouting in the comms only to be repeatedly told to shut up- this was actually the ''real'' agent Pyro, and the girl who had been unmasked and assumed to be Pyro was actually his daughter [[SweetPollyOliver impersonating him]] to protect him from TheMole.
** Played straight in the case of Pterisa. Since she wore samurai armor and a cloth veil over her face to hide her identity, no one knew that she was female until she spoke. This actually happened on two separate occasions: when she was first introduced in [[HubCity LEGO City]], and when she met up with the rest of the cast in the [[TempleOfDoom Maelstrom Temple]].
%%* Hilariously parodied in ''Website/TheOnion'' story [[http://www.theonion.com/content/node/31739 "Hotshot Test Pilot Removes Helmet, Reveals Female Status"]].
* The main character's gender in ''Literature/FightingMonsters'' isn't revealed until several chapters in, when it becomes a twist that she, the first superhero, is a woman.
* In the fifth season of ''WebVideo/TheGuild'', [[spoiler: Zaboo's two Master Chief lackees]] are revealed as hot girls.
* Cordell the dark elf from ''Website/GaiaOnline'' was not particularly concealed, just androgynous, having been introduced as a champion of the dark elves willing to compete in the ([[AbortedArc non-canon]]) Reject Olympics on behalf of Durem. She was found to be female when an aggressive YaoiFangirl [[NoFourthWall invaded the track]] and [[SkinshipGrope felt her up]]. "[[MemeticMutation Hay UR not a bishie!]]"
* ''LetsPlay/TwitchPlaysPokemon'' has Air the Lapras. For the entirety of the stream, it was assumed to be a male. However, transferring it to Generation II shows it to be a female. By analyzing her stats, it was also found that Flareon the False Prophet/Martyr was also female.
* ''Roleplay/WeAreOurAvatars'': When Michelle took Proto Man's helmet in order to repair him, it turns out that Roll was impersonating Proto Man the whole time.
* It's not unusual for some of the kittens fostered in ''WebVideo/TheCritterRoom'' to be given a name under the assumption they were one gender before it is discovered they are actually of the other. Sometimes this means the name has to be changed, but if the name or a nickname is gender neutral, it can stay the same.
* In the parody article [[http://the-toast.net/2013/11/15/empowered-female-heroine/ "A Day In the Life of an Empowered Female Heroine"]], the character in question is so tough she somehow does the reveal as the first thing when she wakes up.
--> She woke up like she did every day: slowly pulling her motorcycle helmet off, then shaking her head slowly back and forth to reveal a long, blonde ponytail. Everyone gasped. “That’s right,” she said, kicking the winning football goal before sliding into a sheer, sexy camisole under a blazer and playing as hard as she worked, “I’ve been a girl ''this whole time''.” One of the guys, the real sexy one, shook his head in slow motion, as if to say “wh-wh-wh-whaaat?” You know the kind. His mouth was kind of open while he did it. He was totally blown away.

[[folder:Western Animation]]
* Sarasim in the ''WesternAnimation/TeenTitans'' episode "Cyborg the Barbarian". Cyborg is her "Bob."
* In the 2003 ''WesternAnimation/{{Teenage Mutant Ninja Turtles|2003}}'' series, the turtles meet a lithe blue mutant called Quarry, leader of a pack of formerly human test subjects of Shredder's weird genetics experiments. When the turtles are able to find a (range-limited, at first) cure, it is revealed to their surprise that Quarry is a woman (in a much later episode, she remembers that her name is "Sydney"). Helped along even more, is the fact that they watched a video where they see a [[RedHerring man strapped to a table and turned into something that looked like Quarry.]]
* The ''WesternAnimation/XMenEvolution'' version of X-23 isn't revealed to be a girl ''or'' a young teenager initially, though she did look awfully ''small'' for a ninja/secret agent/whatever she was supposed to be disguised as.
* Red Claw, a villain created exclusively for ''WesternAnimation/BatmanTheAnimatedSeries''. A terrorist leader whose name was notorious internationally, almost no-one knew that she was a woman at first. Even ''Batman'' was a little surprised when they first met:
-->'''Batman:''' Red Claw is a woman?\\
'''Red Claw:''' Is that a problem?\\
'''Batman:''' Not at all. I'm an equal-opportunity crime-fighter.
* A variation of this occurs in the ''WesternAnimation/BatmanBeyond'' episode "Payback", in which Batman (Terry) faces a dangerous KnightTemplar vigilante named Payback who is willing to harm and kill people for perceived injustices. Because of Payback's deep voice and large, imposing physique, Terry initially suspects him of being either a doctor at a local community center or his bulky henchman. [[spoiler:Payback later turns out to be the doctor's young son wearing an armored suit.]]
* Parodied by Quackor (The Foul), the EvilCounterpart of (Dial "M" For) Monkey in ''WesternAnimation/DextersLaboratory''.
* In one episode of ''WesternAnimation/{{Doug}}'', auditions are held for Bluffington's baseball team, and one kid who always wore a catcher's mask during the audition exhibits sheer excellence in hitting the ball, catching the ball, and throwing the ball. Coach Spitz recruits the star to the team and asks his name, and at that point the star player removes the mask and reveals herself as Patti Mayonnaise. After this revelation, Coach Spitz rejects her just because she's a girl.
* ''WesternAnimation/SpongeBobSquarePants'' parodied this trope, when Sandy Cheeks took off her diving suit in one episode. [[TheDitz Patrick]] exclaimed in shock "Sandy is a girl?!" even though everyone in Bikini Bottom was already aware (hell, Patrick himself already knew; it was the entire point of her debut episode).
%%** Played straight in the medieval episode.
* ''WesternAnimation/FamilyGuy'':
** Chris is conflicted over kissing a friend named Sam... Until he finds out she's a girl. Then inverted when he gets too nervous to speak to her now that he knows she is a girl, until she states to him to keep thinking that she is a guy. Which he accepts.
--->'''Sam''': Do you want to go to the creek and make out?
--->'''Chris''': Yes sir! (walks off with her while holding hands)
** Peter ends up on house arrest when he gets angry at someone who he assumes is a man, and punches "him" out. Not only was "he" a woman (a very masculine-looking woman) but she was pregnant.
** An episode features a talk show where it's [[http://www.youtube.com/watch?v=TCQBZmT2M8c revealed that a girl's boyfriend]]... [[spoiler:is a woman. Actually, a horse. Actually, a broom.]]
* In the second season of ''WesternAnimation/{{Wakfu}}'', [[spoiler:the Masked Boufbowler]] ends up as this.
* ''WesternAnimation/TheSimpsons'':
** Parodied in ''Homer Of Seville'' when Homer was being chased down by a horde of rampaging Opera fans (ItMakesSenseInContext) and was saved by a helmeted motorcyclist dressed in black leathers. When the errant saviour takes off the helmet she says "That's right I'm a woman" in [[MundaneMadeAwesome an overdone way]] before Homer remarks in [[DullSurprise stilted speech]] "A lady motorcycle driver. What is this, ''Franchise/TheTwilightZone?''"
** Kang and Kodos are two OctopoidAliens who mostly appear in the "WesternAnimation/TreehouseOfHorror" specials. Despite them both having [[CrossdressingVoices very deep, masculine voices]], in one Kang introduces Kodos as "my sister." After that, NegativeContinuity makes the issue [[AmbiguousGender ambiguous]], with Kodos often being referred to as male; "[[Recap/TheSimpsonsS26E6Simpsorama Simpsorama]]," however, implies that ''both'' are female. (After all, Kang never said "he" wasn't...despite an episode where [[HalfHumanHybrid (s)he was Maggie's biological father]].)
* An old ''WesternAnimation/LooneyTunes'' cartoon features Daffy forming a rivalry with a small duckling. He realizes he can't bring himself to hurt someone that small, so he uses Phlebotinum-powered growth pills to force the duckling to grow to his size... only he can't bring himself to hurt ''her'' after that, either. There are other things he can bring himself to do with her, though...
* In ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy'', Mandy does a classic by pretending to be a boy on Billy's baseball team, Billy believing girls can't play baseball even though Mindy has a team of her own (which she uses to beat them silly twice).
* ''WesternAnimation/DannyPhantom'':
** Danny sicced a Silver Purple-Backed gorilla named Sampson on Skulker. Danny soon finds out Sampson's real gender when he got an accidental eyeful, and was renamed "Delilah" when he submitted his findings to a magazine.
** One episode that involved a video game which Danny and Tucker are wrapped up in, but they can't defeat a gamer who constantly outwits them at every turn. Near the end of the episode they find out the gamer is Sam, which is humiliating--earlier in the episode, they mocked Sam thinking that because she's a girl, she wasn't good at gaming. So her smugness in the reveal is justified. It also didn't help that they flat out stated their strategies right in front of her which is why she could easily kick their butts every time.
* ''WesternAnimation/AvatarTheLastAirbender'':
** Smellerbee who was dressed like a boy and, despite having a girl-like voice, made it hard to tell which gender she was. It wasn't until "The Serpent's Pass" episode when Jet's group meet Iroh and Zuko that her gender is revealed after Iroh mistakenly classifies her as a boy and she angrily corrects him.
** In the episode "Warriors of Kyoshi", Sokka is surprised (to say the least) to find out that it wasn't men who ambushed them but a pack of teenaged girls.
** For the viewers, a good chunk of the Fire Nation army, if Zhao's speech in "The Blue Spirit" is anything to go by ("We are the sons and daughters of fire, the superior element!")
* On an episode of a Saturday morning cartoon based on ''Raggedy Ann and Andy'', Ann and Andy get rescued by a helmeted, laser toting space warrior. Warrior turns out not only to be a girl but a [[EverythingsBetterWithPrincesses princess]].
* WordOfGod states that Flaky from ''WebAnimation/HappyTreeFriends'' is, in fact, a girl.
* The ''WesternAnimation/SuperMarioBrosSuperShow'' had a {{Franchise/Zorro}}-themed episode, where the Zorro {{Expy}} turned out to be the waitress from the local cafe, who's exposed at the end of the episode when she forgets to take off the mask and fake mustache.
* ''WesternAnimation/{{Futurama}}'': Leela did this, but with a PaperThinDisguise, so only other characters were surprised.
* A variation in ''WesternAnimation/KimPossible'', during "A Sitch in Time", Rufus 3000 warns Kim that one of her enemies would become The Supreme One and take over the world in the future. When Kim captures Dr. Drakken, Monkey Fist and Duff Killigan, she announces, "We captured the Supreme One!" Rufus 3000 answers, "But I don't see her!" Rufus 3000 then reveals the true Supreme One; [[DragonWithAnAgenda Shego]]. Lampshaded of course:
-->'''Rufus 3000''': Wasn't it obvious that Shego was the only villain intelligent enough to conquer the world?\\
'''Kim''': I just thought that taking over the world was such [[MarsAndVenusGenderContrast a 'guy' thing]].
* In the ''WesternAnimation/GIJoeARealAmericanHero'' episode "In The Presence of Mine Enemies", Slipstream has a dogfight with a Cobra pilot, taunting each other over the radio. When they both crash, Slipstream is shocked to discover his opponent is a woman, which is strange because her voice over the radio was clearly that of a female.
* Yanit from ''WesternAnimation/TheMummyTheAnimatedSeries'' turns out to be SweetPollyOliver. Ardeth finds out and decides to let her stay.
* In ''WesternAnimation/Ben10Omniverse'', Kevin is the first person to notice that Khyber's pet, whom he adopts after Khyber abandoned it, is a female.
* In the ''WesternAnimation/{{Archer}}'' episode "Coyote Lovely", Archer, Lana, and Cyril are sent to the Texas/Mexico border to apprehend notorious human trafficker Moreno. Everything is fine until Moreno is revealed to be an incredibly attractive woman, and Archer immediately decides that cozying up to her is more important than his mission.
* In ''WesternAnimation/DynomuttDogWonder'', the criminal Ironface is revealed to be the Serpent Lady.
* {{Discussed|Trope}} on ''WesternAnimation/SouthPark:'' [[TokenEvilTeammate Cartman]] is obsessed with finding out [[TheCowl Mysterion]]'s secret identity and begins grilling all the guys at school. [[TheSmartGuy Wendy]] passes by and casually wonders why he assumes Mysterion is a boy at all. Cartman immediately looks shocked and suspicious of Wendy. ({{Subverted|Trope}}, however, in that Mysterion ultimately turns out to be male.)
* ''WesternAnimation/SamuraiJack'':
** In "Princess Mira and the Bounty Hunters", there is a masked bounty hunter who everyone assumes to be a man. They are all shocked when she takes the mask off, revealing her identity as Princess Mira.
** In "Jack and Farting Dragon", the dragon seems male at first, talking to Jack in a masculine voice. When Jack decides to help it by crawling inside its stomach to find out what's making it sick, he eventually learns otherwise: the reason is [[MonsterIsAMommy a baby dragon that is partially hatched]], lodged in the obviously female dragon's womb.
* In ''[[WesternAnimation/{{Ninjago}} Ninjago: Masters of Spinjitzu]]'', a mysterious samurai in a mech suit shows up to rescue/show up/help the ninja on multiple occasions. Everyone assumes the samurai to be a man, and the scary-sounding voice changer didn't help. Turns out, not only is the samurai a girl, but she's Kai's sister Nya. Needless to say, everyone was utterly shocked.
* In ''WesternAnimation/TheSecretShow'', a villain called Dr. Hypno was eventually revealed as a woman, which shocked even former rival and retired secret agent Zach Meadows. [[spoiler: And then they got married.]]
* Parodied as is everything else in ''WesternAnimation/RobotChicken'' in a skit called "Codfish" where it turns on in ''WesternAnimation/InspectorGadget'' that Dr. Claw is actually a very overweight woman and has been doing all this because she is in love with Gadget. Then in ''Series/CharliesAngels'' that Charlie is actually a teenaged boy who gets off on hearing them recall their adventures in erotic detail (they seem to find it makes a lot of sense after this), and that God from Noah's Ark was just a guy with a loud speaker that wanted Noah to build him a boat. And lastly it is revealed that the host himself is actually a Codfish.
* In the ''WesternAnimation/SuperRobotMonkeyTeamHyperforceGo'' episode "The Hills Have Five", one of the members of the Wild Five is a hair monster. Much to the surprise of everyone (including the viewers), not only is the monster a girl, but is also the biker leader's main squeeze.
* Lord Dominator from ''WesternAnimation/WanderOverYonder'' disguises herself as a [[KnightOfCerebus dead serious]] intimidating male, but beneath her armor she is a dorky, but still evil, teenager.
* ''WesternAnimation/ScoobyDooAndScrappyDoo'': In "I Left My Neck In San Fransisco", Lefty Callahan, who is mentioned offhand earlier in the episode, is revealed to be a woman.

* [[https://en.wikipedia.org/wiki/Chevalier_d%27Eon Chevalier d'Eon]] kept people guessing until the very end.
* There was a stagecoach driver in the American West named [[http://en.wikipedia.org/wiki/Charley_Parkhurst Charley Parkhurst]]. One-eyed Charley was known for his toughness and could handle anything, up to and including armed bandits. After his death (at age 67), the person who laid him out discovered "Charlie" was a woman, and her birth name turned out to be Charlotte.
** A tribute of sorts is given in the second and fourth ''Blackadder'' series, where a girl named Kate pretends to be a young man named Bob Parkhurst.
** A similar discovery was made about jazz musician [[http://www.straightdope.com/columns/read/1060/whats-the-story-on-the-female-jazz-musician-who-lived-as-a-man Billy Tipton (nee Dorothy Lucille Tipton)]], following Tipton's death. Even Tipton's adopted sons and at least one sexual partner didn't know Tipton's true sex.
* Lots of people tend to call unfamiliar dogs "boy" on first sight, [[FemaleFelineMaleMutt assuming they're male]] until proven otherwise. This used to be {{inverted}} in some parts of Israel (particularly in UsefulNotes/{{Jerusalem}}), where every unfamiliar cat was referred to as female until proven otherwise. In the past couple of decades this has reversed, so that now the trope is played straight.
* A non-human example is Cher Ami, a pigeon who saved many lives in World War I. She was thought to be male, and her gender wasn't discovered until after her death. She's still referred to as male sometimes, however.
* ''My God! It's a Woman'', the biography of Australian aviatrix Nancy Bird.
* The ScienceFiction author James Tiptree Jr. was discovered, after much controversy and one prominent author penning an essay on how it was ''impossible'' and ''inconceivable'' that James could be a woman, to be a lady named Alice Bradley Sheldon. The fact that she wrote many stories where gender took a major role did not help. George Sand, birth name Lucile Dupin, also qualifies.
* Creator/JKRowling. Apparently, some people were surprised to learn the real name. This was [[MoustacheDePlume deliberately invoked]] by the publisher because their initial target audience was young boys who they felt might be put off by a female author.
** This is pretty common with female authors who write outside traditionally "feminine" genres. [[Literature/TheOutsiders S. E. Hinton]]. Creator/KAApplegate. Creator/CJCherryh. [[Series/StarTrekTheOriginalSeries D. C. Fontana]].
** In July 2013 it emerged that "Robert Galbraith", author of the crime novel ''Literature/TheCuckoosCalling'', was in fact Rowling. Sales on Amazon promptly jumped ''150,000%''.
* In the olden days, women who ran businesses would often take advantage of this or run the business through their husband, the legal owner.
* Inverted after ''Discworld/EqualRites'', where many assumed Terry Pratchett to be a woman based on the book's feminist themes.
* Jack Prelutsky's children's poem "The New Kid on the Block" describes the titular new kid as a terrible [[TheBully bully]] who "likes to fight and picks on all the guys"; and ends with the line, "I don't care for her at all".
* [[http://www.youtube.com/watch?v=whEVftJWBjA&NR=1#t=2m8s A beautiful real-life example, except for the fact that it says "Samantha" on the side of the cockpit.]]
* GenderFlip: The video [[http://www.youtube.com/watch?v=_TBd-UCwVAY "It's Time"]], shot from the perspective of someone who falls in love with a man and builds a relationship with him. The video ends with the man proposing marriage, and the camera pulls back to reveal that the point-of-view character was [[QueerRomance another man this whole time]]. The video was heavily promoted by gay marriage advocates, causing many people to [[ItWasHisSled not even realize that the POV character's gender was supposed to be a]] TwistEnding.
* RealLife example: In the 2012 Orange Bowl, a West Virginia player celebrated by tackling the Orange Bowl mascot. [[http://www.youtube.com/watch?v=xsK6OKfLCqo This]] is his reaction upon learning that the mascot was played by a woman.
* [[http://www.youtube.com/watch?v=Q5aam4MpZss The first trailer]] for ''The White Queen'' has this [[RuleOfThree three times over]].
* In [[UsefulNotes/ChineseLanguage Chinese]], the words for he and she are pronounced exactly alike (but are written differently). In spoken Chinese, this can lead to [=SIAG=] moments if the subject has a GenderBlenderName or the listener does not have enough context from the sentence to get gender.
* Creator/VCAndrews, AKA Virginia Andrews, said in an interview for ''[[http://www.completevca.com/art_fear.shtml Faces of Fear]]'' that many of her readers were unaware that she was a woman. This resulted in fan mail referring to her as 'Sir' and even female readers sending photos with little or nothing on! Inverted after Andrews' death with her ghostwriter Andrew Neiderman. While long time fans have known the truth, some newer readers are unaware that the books written after 1986 are written by a man.
* M.Brundage, cover illustrator for Magazine/WeirdTales, and one of the {{Trope Maker}}s for the association of MonsterMisogyny, GoGoEnslavement, and several other forms of ContemptibleCover with fantasy and science fiction. Like many people today, both contemporary fans and MoralGuardians were surprised to learn that the "M" stood for ''Margaret''. To further confuse everyone, she was married with a young son during her time with the magazine.