KidIcarus: Gosh-a-cus, Princess Lana! 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!
Samus Is a Girl is when an action girl 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, 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 Tomboyish Name or Gender-Blender Name 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' 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 You Didn't Ask. Or because she's just one among a whole Badass Army, so nobody paid attention specifically to her. Or because she's a complete stranger that nobody had seen before.
See The Faceless and the Hackette, a Sub-Trope. Contrast Unsettling Gender-Reveal (where "Alice" turns out to be "Bob"), Sweet Polly Oliver (Samus Is a Girl from a viewpoint that already knows she's female) and Viewer Gender Confusion (where the audience, not the characters, don't know what gender Pat is). See also Geeky Turn-On, which is sometimes related to this. Female Monster Surprise is a similar trope, but with a monster. May involve Gender Misdirection.
Please, don't bother with the spoiler tags here. The name of this trope is a pretty good reason why this should not be.
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Named for Samus Aran from Metroid. In the first game, the player doesn't learn she's female until after guiding her through an army of alien baddies. Later games in the series still play with this. The Prime series, however, does not play with this, and gives her a rather feminine figure considering she's in armor. They also let you see her eyes through her visor. And Prime 3 even showed us her being a woman at the start of the game. Other M completely throws away this, however, 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 cheat code "Justin Bailey" entered in the first game, will start Samus near the end of the game, with no armor on.
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 throw it in moments in video game history.
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.
Naturally, this happens to our favorite SPARTAN in Haloid as well. Wait.... Surprise! That's not Master Chief, but Nicole-458, a female SPARTAN who appeared in the Dead or Alive games (even though there was no canon on how Nicole looked like). She ends up pulling this trope on Samus, making Haloid a double whammy.
Played with a little bit in Super Smash Bros. Brawl, if the player fights her as 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.
These conversations may also be subtle foreshadowing of the Power-Suited Amazon Brigade that would appear in Metal Gear Solid 4. It's not the only thing Hideo Kojima foreshadowed in that game.
In 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 Nintendo Power). All the winners who had Samus unmasked in their art depicted her as a man.
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 '80s Hair. 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.
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 Bug War and seeing nothing but Nightmare Fuel for a solid 5 minutes can do that to you.
In the "Battle Tendency" arc or JoJo's Bizarre Adventure, Joseph Joestar and Caesar go to meet Caesat'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.
Rei in the manga version of Neon Genesis Evangelion when she's still inside the Eva. 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 sees Rei, it's clear she's a Bandage Babe — along with all sorts of other types of fanservice / Fan Disservice.
Carefully averted in Rebuild of Evangelion 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 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, 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 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.
Cagalli Yula Athha of Gundam SEED's 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 Naomi Shindo usually voices young boys.
Akane exemplifies the trope when she dresses up in full kendo outfit and protection and participates in a males-only match against Tatewaki Kuno. It is only after girl-Ranma declared her love for whoever was in there and then her mask falls off (long story) that the audience and Ranma realize that they had been cheering for Akane all along.
A more handy example lies with Ranma's Unlucky Childhood Friend Ukyou. Having met her at a very young age, Ranma always believed her to be another boy; after a bitter grudge match in which she forced him to fight "seriously", he was stunned to discover she was actually a girl. Hilarity Ensues:
Ranma: Since when are you... Ukyou: ...a girl? Since I was born, idiot. [Ranma pours hot water on her] Ukyou: Ow! Hot! Hot! Hot! [punches Ranma] Why the heck did you do that?! Ranma: Hey, you didn't turn into a man!? Ukyou: What's that supposed to mean? Listen up and well! I'm a 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 Konatsu and Tsubasa, 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 their outfits are destroyed, one way or another.
In 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.
In the anime 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 YuYu Hakusho. 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 Excel♥Saga concerns a mysterious masked man with a masculine voice. He and Nabeshin have a lot of Ho Yay, which Excel comments on - and then the mask is removed, showing a beautiful blond woman. Still with a masculine voice.
A bit of a drawn-out occurrence appears in Katekyo Hitman Reborn!. 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 Sailor Moon, 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, 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.
Lan Fan in Fullmetal Alchemist. When Ed uses alchemy to destroy her 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 already has her own (there was a brief, mostly-played-for-laughs Ship Tease between Lan Fan's love interest and Ed's, though).
Also Major General Olivie Mira Armstrong, when Alex first mentions her, she could have been a male as well.
Kidd Summers at the start of the Pokémon 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.
Yellow in the manga Pokémon Special. Funnily enough, only Blue and Blaine knew until near the end of the Gold/Silver/Crystal arcs, then everyone finds out after she removes her hat.
Green found out while training her. The only ones shocked by that spoiler were Red, Crys, and later Gold.
Anabel and Angie in the main anime. Incidentally, they both end up developing a crush on Ash.
Ash's Aipom, actually. It's hinted but never really confirmed until we see her wear a dress in one episode.
Zoroark turns out to be female in the movie.
Georgia's Pawniard/Bisharp, despite being voiced by a man, is revealed to be female in her debut episode.
Due to the voice acting in the dub, German viewers often thought Digimon Tamers'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 Digimon Xros Wars 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 Steel Fist Riku. 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 Mahou Sensei Negima! 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 breasts boobies that bordered on the obsessive. Most readers found this character quitedisturbing... until a recent chapter mostly set in a bathhouse, where the hunters are encountered again under peaceful circumstances, and Paio is revealed to be a girl, who proceeds to Skinship Grope 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 Double Standard, 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 in costume (Commanding the tentacled worm) with her out of it (Furo, remember? so may not be Work Safe).
What Double Standard? Ku Fei didn't hold back when she kicked Paio in the face.
Mostly by the fans, who were creeped out by Paio Zi at first, but then laughed their heads off when the truth came out.
There is a difference between Skinship Grope and what seems like attempted rape.
Fist of the North Star 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 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'll jump in and save the day. Then you end up surprised when the "woman" in the pink cloak turns out to be said martial arts badass Rei in disguise, luring said thugs to him.
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.
Reversed in Liar Game in the second round where the seemingly innocent "Yuji" is revealed to be the cross dressing Mr. X.
Glass Fleet combined this with Viewer Gender Confusion because Michel had a female voice actor. The big reveal isn't until episode seven. Afterwards, her style of dress does not change (spoiler text as this is a major plot point of the series).
In Yu-Gi-Oh! 5Ds, 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 Lady of War theme, like Sherry herself, and flower-themed Trap Cards.)
Kino's Journey: 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 Crossdressing Voices, 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.
Full Metal Panic!: In the Second Raid, Mithril agent Wraith is revealed to be 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), Hayate the Combat Butler is setting itself up for this one. The other characters even think Red is a guy, despite the significant lack of male form (not just Hina'sPettanko status).
In Kirby of the Stars, 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.
In Death Note, 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 Space Pirate Mito. During a fight, Big Bad 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 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 One Piece 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 Angel Sanctuary. The promising scientist Lailah's success elicited jealousy from her male peers, who raped her. Branded a Fallen Angel for becoming "tainted", she sold herself in desperation to 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.
Used during the Naruto 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 in fact the new daimyo who had assumed lordship, and that said daimyo was in fact the daughter of the dead daimyo and had been posing as her also dead brother.
Subverted much earlier during the Land of Waves of arc. Haku's first appearance showed her to be highly-skilled and convinced even Kakashi that 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 Unsettling Genderreveal.
In 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 bishie man.
Ice Revolution: 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.
The red man in Deadman Wonderland. Ganta is so screwed when he found out the nemesis he hated so much turns out to be his childhood sweetheart Shiro.
Kei in Iria Zeiram The Animation. 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.
In episode 12 of Blue Exorcist, Yamada, who always wore a hood and never spoke, turns out to be Stripperific Action Girl 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 The Reveal.
The titular character in Osamu Tezuka's Dororo. It doesn't help that she was told she was boy by her parents.
In Sgt. Frog, 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 ARMPIT Platoon. 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.
And as a little extra, Charles/Charlotte also happens to be a Char Clone and later becomes a Love Interest for Ichika.
And as a litlle extra extra, her nickname, given to her by Ichika, IS Char. Go figure.
Fushigi Yuugi has Soi, who was a person wearing a cloak for a few chapters before revealing herself as a woman.
A villainous example appeared in Brain Powerd - the enigmatic Baron who begins to appear late in the show is quite fearsome, helping the villain Jonathan transform his GrandCher into a borderline Eldritch Abomination known as the 'Baronz'. His reasons seem mysterious and Chess Master-y, but... 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.
The acolytes in Agnis Philosophy are all presented to the viewer as robed, hooded individuals, so the viewer can be forgiven for assuming they are male until the titular character pulls off her hood, revealing that "he" is, in fact, a she.
In A Certain Magical Index, the villainous organization GREMLIN, which is mostly made up of people with Norse Mythology gimmicks, is led by someone called Odin. Surprise, Odin is Othinus, who looks like a 13-14 year old girl and is still powerful enough to Curb-Stomp Battle pretty much anyone since she indeed has the power of the Norse God Odin.
Lupin III Princess Of The Breeze 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 Armor-Piercing Slap, and Lupin getting knocked off of the airship.
In the Gaiking CGI test footage, the pilot was revealed to be a woman. In its previous incarnations, Gaiking's pilots were both male.
In Tokyo Ghoul, the legendaryOne-Eyed Owl is revealed to be a young woman beneath layers of Kakuja armor and baggy robes. Her father was able to impersonate her convincingly more than once, leaving it clear few people suspected a woman beneath the monster's armor.
One of the regular supporting heroes in Paul Grist's Jack Staff 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 Spider-Man vs. 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 X-Men, Professor X's primary love interest Lilandra was introduced in a running subplot in which he was having ominous visions of space battles and a menacing armored figure. When the figure finally showed up and took off its helmet, it wasn't quite what he was expecting.
Mindf**k of Empowered is a dramatic example, as eventually revealed to Emp; Mindf**k and Sistah Spooky are ex-lovers, whose first meeting (without a Samus Is A Girl scene) was shown in flashback the following volume.
Junior, who is assumed to be Ragdoll's brother or father in Secret Six, turns out to be his sister.
Sasquatch from Alpha Flight is usually male in the main continuity, but in the 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 Marvel Universe is the werewolf Wolfsbane. There were some hints to this beforehand though; readers may have wondered why "he" had 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.
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 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 The Sandman, 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.
The Surrogates features a setting where normal people no longer interact with each other in person, but instead use a 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 Corrupt Corporate Executive 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 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 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 Atari Force second series was referred to as being male up until Morphea discovered Taz was pregnant.
In DC's 1980s comics series Arak Sonof Thunder, 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 main/cover story of one 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 Avengers run introduced Iron Man 3030, a futuristic Legacy Character. 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 mixed-race granddaughter, Rhodey.
Heavy Metal: 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, everything else to keep up the film's quota).
Technically, the stitchpunks of 9 are asexual constructs. This trope is still invoked with 7, whose female voice isn't heard until after "she" has demonstrated "her" combat prowess.
The Dragon turns out to be this in the original Shrek.
From Sky High, power-armoured supervillain Royal Pain turned out to be 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.
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.
This seemed to be the idea behind Nyssa's first scene in Blade II. 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.
Thunderball. A motorcyclist kills a man driving a car (who's chasing James Bond) 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 Dragonslayer (1981) a character turns out to be a girl masquerading as a boy since girls are in danger of being sacrificed to the dragon.
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.
Barbarella in the beginning of the original film, where a bulky spacesuit is removed, and Fanservice ensues.
Terminator Salvation: 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.
Racecar driver A.J. Ferguson in the feature film version of The Little Rascals turns out in the end to be...Reba McEntire, shocking all the young male members of The He-Man-Woman-Haters club.
The Sting has one The hitman "Salino" turns out to be Loretta Salino, the waitress in the diner.
A shocking variant was used in Hellbound: Hellraiser II, 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 a young boy.
This may have been an homage to the infamous use of the same variant in the opening scene of Halloween (1978).
Subverted in What's Up, Tiger Lily??, a Japanese spy movie with new dialog by Woody Allen. 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 Pitch Black, 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.
Pocket Ninjas when the White Dragon at the fight scene near the end was revealed to be Tanya.
Subverted in Aliens. Male Marine to Action Girl 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 The Last Legion, familiarity with those trope allows one to quickly surmise that the Eastern Roman Empire soldier is a chick. Why else would she wear a helm with an aventail like that?
The opening scene of Iron Man 1 has Tony exclaim in suprise when he realizes that one of his three military escorts is actually female (she's wearing BD Us, 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 TRON: Legacy 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 Slasher Movies featuring female killers, the villain's gender is usually hidden by either a disguise, camera angles, Murderer P.O.V., or some combination of the three. Plus, they're probably played by random stuntpeople up until The Reveal.
In Stick It, 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 the Vincent Price film Theatre of Blood Lionheart's lead henchman the British accented guy with the hippie glases, afro, and beard turns out to be his daughter Edwina (Dianna Rigg).
In I Am Legend 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 Your Highness, the heroes meet a mighty warrior in the arena, and are surprised when she removes her cloak.
In The Dark Knight Risesthe 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 Colombiana, the police assume that Cataleya's murders were preformed 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 Waif-Fu to kill.
In Eden Log, the botanist turns out to be a woman when the man removes her helmet.
Comes up early in Zero Dark Thirty as one of the spectator to the torture is revealed to be female, hidden by a hood.
Downplayed in The Fifth Element - 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 Action Girl.
In the 90's The Little Rascals movie, the boys are all excited about meeting a NASCAR driver by the name of A. J. Ferguson. They assume A. J. is a man, because 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 SWAT Team in S.W.A.T., Canon Foreigner "Chris" Sanchez is found at the hospital after having beaten the crap out of a Gang Banger. Hondo is very surprised to learn that Sanchez is a Spicy Latina 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?
Britomart in The Faerie Queene 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 — Love at First Sight for her, Love at First Punch for him.
Bradamante in Orlando Furioso, 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 narrator. This is revealed close to the end of the book.
This happens in one of the 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.
Andre de la Croix in the Time Wars series. Also a Sweet Polly Oliver, but the reader doesn't find out until after she's kicked serious butt at a tournament.
In Esther Friesner's Majyk 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 the hero's wife, disgruntled at being left at home while he's out on an adventure. Even after The Reveal, she keeps up the masquerade, finding swashbuckling to be a rewarding career.
Éowyn from The Lord of the Rings. 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. A Genre Savvy reader will likely have already identified her by that point, though.
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 Paper-Thin Disguise.
In A Song of Ice and Fire, 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.
Terry Pratchett's Sourcery, 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.
The readers 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. 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). The other members vary from "yeah, obvious" to "wait, I thought the big secret [name] was hiding was being a [vampire/werewolf/whatever]."
In Feet of Clay, it's revealed that Cheery Littlebottom is a female dwarf to the reader fairly quickly. As a lampoon on Our Dwarves Are All the Same, Dwarven culture is so male-centric that females typically behave and masquerade as men stated that all dwarves are considered dwarves without distinction of sex. This can cause confusion when two dwarves 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 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.
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 Men at Arms (But she's a w...), it is 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.
Tamora Pierce plays with this trope a bit. The readers know very well that Alanna/Kel is a girl (especially Alanna); it's the various characters who get the shock.
Matt Ruff's Set This House in Order when we find out 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.
In the Conan the Barbarian story 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 Captain Underpants 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.
Harry Potter: 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 Dan Brown's The Lost Symbol. No awesome armor, but a surgically raspy voice and a cell phone connection do the trick.
In Robert J. Sawyer's Calculating God, 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: 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 Patricia Briggs' 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 The Hunger Games 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, "Girls don't hunt!"
In Star Wars: The Old Republic: Fatal Alliance, Dao Stryver is a tall, tough 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 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.
In the Ciaphas Cain novel Duty Calls, Cain is saved by a warrior in Powered Armour 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 Iain Banks's The Wasp Factory, 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 A-to-Z Mysteries 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... then realizes Wallis is really tourist Mavis Green, and the kidnapped man is her brother, Walker.
Jirel of Joiry is revealed this way in her first story "Black God's Kiss".
In James Herbert'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 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 Icerigger, it's not revealed that 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 the Black Company novels, Soulcatcher, one of 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.
A teaser reading from the in progress book 2 of The Stormlight Archive, has revealed that the Parshendi Shardbearer Dalinar fought at the end of book 1 is female.
Dead Mountaineer's Hotel by Strugatsky Brothers has Brun "The child", the teenager of ambiguous gender (said ambitiousness is kept on by unisex clothes, large shades and avoidance of gender endings in words). Her full name is Brunhilde.
In The Dresden Files: Cold Days, the fairy Dresden nicknames "Captain Hook" is revealed to be a girl named Lacuna after she is captured by the heroes and her armor comes off.
Chops the gremlin of City of Devils 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 Mr Blank 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 NaNoWriMo novel And Then There Were Monsters 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 giiirl oh crap.
Jane Yolen's Sword of the Rightful King, a King Arthur retelling, has an interesting twist when the apparent Canon Foreigner Gawen, Merlinnus's teenage assistant turns out to be a young noblewoman named Guinevere.
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 Shout-Out to Claudia Black's previous role in Farscape (see below).
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.
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 Kamen Rider Faiz, 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 Kamen Rider franchise, either because of tradition or extreme and utterly shameless sexism — hopefully, the former — has had exclusively male heroes since it began in the 1970s, with the rare exceptions eventually being 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 Kamen Rider Fourze, 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 Significant Anagram: Sarina Sonoda = Sasori na no da = "I am the scorpion."
Inverted in case of Virgo Zodiarts, when her true identity is Emoto himself. Despite that, similar with Sonoda, his name has significantbackwards 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 MacGyver after she gives Mac a free flight. Get your minds out of the gutter...
The (classic) Knight Rider 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 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.
In 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 bandana covering "his" face. Said mystery "man" often attacked the Infection's valet, Christy Hemme, prompting her to repeatedly complain to on-air authority figure Jim Cornette about the "man-on-woman violence" going on. Of course, the mystery member of LAX later revealed herself as a latina named Salinas, thus making the Rock 'n Rave Infection look like a bunch of whiners. And immediately after The Reveal, her attire went from concealing to stripperiffic. Hey, it is Professional Wrestling after all.
The 2006 series of Robin Hood 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). Considering later events, it makes it a naked second impression as the two become canon.
In one episode of Chris Titus', um, 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 dyke? Yeah.
Power Rangers S.P.D.: the Red Ranger of the SPD A-Squad. Double points for having the Tomboyish Name Charlie. This actually caused a bit of a stir on the Rangerboard forum: one member, being an expert in digital voice manipulation, 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.Crowning Moment Of Awesome?
They tried pulling this off again in 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 Power Rangers Ninja Storm, 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 Ninja School, a fact his dad only learned after she publicly kicked his ass.
From the Bones episode "Fire in the Ice", Albie the poker ring organizer. Booth is very shocked. Perhaps because he recognizes her from his Buffy days?
How I Met Your Mother 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 Get Smart. 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 Merlin, we see 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.
"Remembrance of the Daleks": The Renegade Dalek battle computer is the young girl constantly seen beforehand. Made more effective by having a voice of the opposite gender before The Reveal.
"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 a Cyberman episode, when an unwillingly cyber-converted human rambles deliriously about her wedding plans.
In the less than impressive sequel to the Sam Neil version of Merlin, Merlin's Apprentice Squire Brian turns out to be Squire Brianna.
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.
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 Las Vegas, 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 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.
In Psych, the terrifying Serial Killer Mr. Yang is revealed to be 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 very clearly presenting herself in her letter as MISTER Yang, not just Yang or anything gender-ambiguous. Who says Villains Never Lie?
Arguably subverted/justified in the second sequel to that episode, when 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...until she fell in love with Shawn, and he proved that he was her superior, at which point she surrendered. But there's one rather creepy part of that: she fell in love with Shawn when he was a kid.
In the first scene of the pilot of Lois and Clark 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.
In the 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 Double Take and mouths, "Mom?" Hard not to blame him.
Mulan is introduced this way in the Season-2 premier of Once Upon a Time, initially being a mysterious armored figure.
Person of Interest: Until the season 1 finale, "Firewall," the only thing we knew for certain about Root was that she is a woman.
Ross on 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.
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 is the man I spoke to on the phone?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... struggle with my gender. As if men has a monopoly on murder.
In the pilot of 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 little dancer, who is revealed to be a little girl.
Done in Prison Break, where it turns out that the Vice President of the United States, the primary figure behind The Conspiracy at the heart of the show, is a woman named Caroline Reynolds in the show's universe. Interestingly, the show manages to pull this trope off in reverse, giving the audience several glimpses of Reynolds as a sweet-faced suburban woman tending her garden (just crediting her as "Garlic Cutter" in her earliest appearances) before revealing that she's actually the Vice President.
Witch Hunter pulls this card with Halloween, Tasha's pumpkin-headed marionette who is initially thought to be genderless due to being a marionette and all that, but when Tasha breaks Halloween's first seal, its true form is revealed to be this.◊ Tasha is, naturally, shocked.
The music video for Prodigy'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. 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 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 Pop Gear. They then do the same damn thing the next time they appear in the film, performing "Eyes")
The music video for the Within Temptation/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 Funky Winkerbean, The Eliminator was a Enfante Terrible 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 Shout-Out to Darth Vader, as The Empire Strikes Back was THE hot movie at the time of his debut). Midway through the first Time Skip, 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 Mother Goose and Grimm, Grimm was shocked to learn that his hero, the star of the TV show Karl the Wonder Poodle, was a female poodle named Karla.
In Cirqus Voltaire, when you unmask Voltaire, not only is Voltaire revealed to be a woman, she is also the game's announcer.
Shantelle Malawaski, best known for her work in various independents as Shantelle Taylor and in TNA as Taylor Wilde, wrestled two house show (non-televised events) and one dark match (non-televised matches held before televised events/TV tapings) for WWE in January 2007 in a male disguise as 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.
Played with in Dino Attack RPG. 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 impersonating him to protect him from The Mole.
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 LEGO City, and when she met up with the rest of the cast in the Maelstrom Temple.
Ravenloft had 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.
Also in Raveloft, the Midnight Slasher (an insane Expy of sorts of Jack the Ripper) 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 Yu-Gi-Oh! card game, there's Gravekeeper's Assailant. There was never anything to suggest that the monster on the card was female until she appeared on Yu-Gi-Oh! GX 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.)
Video Games (Excluding Samus)
Interestingly, the eponymous character from the NES game Mach Rider is 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.
Zelda's disguise as the male Sheik in The Legend of Zelda: Ocarina of Time, who was designed with a male character model to keep the disguise more convincing. Programmers admitted she didn't get a more realistic design until 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. Word of God has since stated that this is not so; Zelda can't change her entire body like that, just a few surface details.
And, as of Skyward Sword, guess who/what else is female? The Master Sword. Technically the Skyward Sword, but eventually our old friend.
This is the twist in Akira's ending in Rival Schools: 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 "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 said 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 It Was His Sled), and her helmeted costume (labeled "Powered Akira") is the unlockable one.
Captain Syrup from the first Wario Land is a villainous example; the game's instruction manual even refers to her with masculine terms to avoid ruining the surprise.
Faris of Final Fantasy V. Although she seems to pass for male strictly because 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."
This is the main twist in the ending of the iOS edition of Dead Space. Vandal reveals her true identity to be Karrie Norton as she lies wounded on the floor near the defeated final boss.
Final Fantasy Tactics A2 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.
Toby Masuyo in 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 Mr. Driller series and Namco × Capcom do not play with this trope, opting to have her helmet-less (she's Mr. Driller's mom after all).
Happens twice in Tales of Vesperia. 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) Dragon Rider — which turns out to be Judith. In both cases, Yuri winds up the "Bob". And in both cases, they remain a full-fledged mage and warrior, respectively.
The Cyborg Ninja in Metal Gear Solid 2 is not Gray Fox as in the first game, but instead Olga Gurlukovich.
The last target in Assassin's Creed I is not there when you go to kill him. The person disguised as him is revealed to be a woman after 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.
The Power Armor in the Fallout series has always been gender neutral, but hearing a female voice from the Power Armor speakers in Fallout 3 caused players Samus Is A Girl spit-takes.
Before then, most power-suited Enclave soldiers in Fallout 2 were actually female. Even some that you spoke to.
Data in Vault 87's Chief Physicians Terminal, along with word from voice actor Wes Johnson, suggests Fawkes was female before becoming an asexual Super Mutant.
Fallout: New Vegas has two (formerly) 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.
Naoto Shirogane in Persona 4. With the twist that the party finds out when they show up to rescue her, rather than her rescuing them.
Portal plays with this, in that the 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. In the sequel, Wheatley passively assumes that whoever beat GLaDOS was a guy, and is taken aback when he finds out that it was you.
The first Destroy All Humans! 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.
Word of God states that this was to have been the big reveal at the end of the fifth game in the old ZX Spectrum Magic Knight series (Finders Keepers, Spellbound, Knight Tyme, Stormbringer and...). Possibly Older Than The Nes, 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 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. 3D graphics weren't that good at the time of the first Tekken, however.
And there is also Leo from Tekken 6, who 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". Confirmed to be female by Word of God.
In the game by Tim Schafer, Brutal Legend, 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 Dragon Quest Monsters, the 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 Paper Mario: The Thousand-Year Door, 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.
Sly 3: Honor Among Thieves gives us 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 Gadgeteer Genius Penelope, who created the disguise to get around the dogfighting league's age restrictions.
The mysterious scrambled voice in the marine campaign in Aliens Vs Predator 2, though she never actually does any fighting.
Black Widow from 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 tall and muscled female wrestler.
The video game series Guilty Gear is notorious for pulling off a reverse of SIAG (Bridget needs no introduction), but what many people don't know is that Word of God 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.
Shale from Dragon Age: Origins is 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 Mirror's Edge, Faith spends part of the game chasing after an assassin - who is also a runner like herself - who Faith assumes to be male. Much later, when Faith gets into combat with said assassin, it is revealed that it is none other than her treacherous best friend, Celeste.
Jack (AKA "The Convict"; AKA Subject Zero) in Mass Effect 2. She's never actually physically disguised, but all you know before meeting her is that she has a Tomboyish Name and a nasty reputation. This reveal was spoiled in the advertising.
Chris from Princess Waltz is taken to be a man by the main character. Even despite many hints and on mutiply occasions fusioning together to become a woman, the main character doesn't realize that Chris is actually a girl untill... well... Either way even the main character feels stupid for not getting the hint before.
Monica from Dark Cloud 2 first appears disguised as a young child when you first meet her, and after she defeats the Monster Clown who was trying to seize Max's MacGuffin, removes her hood and reveals herself to be a woman.
Alexis of Valkyria Chronicles II. 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 Growlanser. Her portrait is a giveaway when you first meet her as an Imperial Knight (you can see she has cleverage if you examine closely the portrait where she hold her sword) It was stated that Imperial Knights does not allow females to join, thus she hid her gender (though her 2 fellow companions Oscar and Lyell already found out and choose to ignore).
Jayle from Valkyrie Profile. A noblewoman Jeanne d'Archétype 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 fallen for her.
In Disgaea 2, everybody assumed Overlord Zenon is a male, but turns out Rozalin was the reincarnated Zenon, though the game's "reincarnation" mechanic allows non plot characters to reincarnate into any class, even opposite sex ones.
Note that Rozalin is very clearly female. This is more of a case of The Girl Is Samus.
Subverted in Hydorah. Throughout the game, the player character is conspicuously helmeted, but is revealed in official artwork to be male
Dragon Fable 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 Newsletter.
The player character of Faria is only represented by an androgynous Super-Deformed sprite, and gender is not revealed until after she's saved the princess (the fake one, that is).
Subverted with Alex Wesker in Resident Evil 5's DLC "Lost In Nightmares." Fans initially assumed that Alex Wesker was likely to be female due to a lack of third person gender identifiers in the memo revealing Alex's existence. However, the lack of gender pronouns was in fact the result of a shoddy localization attempt by the localization team. In the Japanese version, it is made very clear that Alex is male.
Ōkami had this happen around Amaterasu, as some refered to Ammy as a male, other as a female, and this has led to fans to argue among themselves over it. A known fact is, however, Deities can have whatever gender they please, and the Amaterasu of Shinto was originally female... But this one is the reincarnate Shiranui, which was deemed male... What's the truth? It was never known until...
The Sequel revealed Amaterasu's true gender! 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 the revealing above happened, the arguments in favor of Ammy being male were because of the leg lifting when using Golden Fury. Except dog owners would contradict that by knowing both male AND female lift their leg when marking territories. So it was often a flawed evidence.
In Jays Journey, 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 Rhythm Thief & the Emperor's Treasure, Charlie/Claude is the inspector's son and basically a thorn in Phantom R's side... but 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 Starcraft: Brood War was revealed to be Selendis, a female Protoss executor.
During Mighty No. 9's Kickstarter campaign, when discussing Mighty No. 8, the developers revealed that they initially planned to have Two Girls to a Team 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, Keiji Inafune, liked the design, so it appeared that Mighty No. 3 was subjected to The Smurfette Principle... until a later update long after the Kickstarer campaign revealed that Kimo Kimo made 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.
One puzzle in Professor Layton Vs Phoenix Wright Ace Attorney involves this. The 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 the culprit was the knight, who is actually a woman under the armor.
Throughout Tales of Xillia and Tales of Xillia 2, the player is told about the Genesis Sage Kresnik, the first person to summonMaxwell 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.
Fate Nuovo Guerra follows tradition and chocks one up with a certain Lancer from The Trojan War, though it wasn't so much a disguise as it was "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, Natsu initially cringed at the idea of turning Saber into a female.
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.
Dangan Ronpa has this twice: In Chapter 2, 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 "he" was named Genocider Jack before The Reveal, and Genocider Jill afterwards. Then in the final trial, it is revealed that the person behind Monokuma is Junko Enoshima.
Miko Miyazaki from The Order of the Stick 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, judging from Roy's reaction, fairly attractive). Roy plays her Bob for a while, until he gets put off by her personality. This wasn't that drastic, as she seemed more ambiguous than masculine prior to this.
Before The Reveal, she doesn't even seem to be human.
Also initially appearing as a hooded figure was the previous Wotch, Miranda West of The Wotch. Her initial appearance was in the very first story arc. Her reveal was at the end of the fifteenth.
Ashido from Inhuman is shown to be an example of this when another character walks in on her changing.
Pratos the Bounty from Jix ends up being both a female Ambis named Aranis and Jix's cousin. A possible nod to Samus Aran.
Jix herself 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).
Shadow from A Modest Destiny. She spends a good amount of time in the comics as this until an incident where Maxim grabbed herbreast, and it's not shown who she is until much later.
When the previously killed Crimson Blade shows up at 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.
In a subverion of the usual way this trope is carried out, even after The Reveal her appearance is never feminine in any way. The sole differentiating factor is really her voice.
Later zigzagged with CT. Upon the first encounter CT appears to be a male in all respects. Season 9 reveals that CT was actually a woman. Then season 10 reveals that the original CT died and that the CT in the desert was her boyfriend who took her name and helmet to honor her.
Count Repugsive in Nodwick. The reason she gives for the deception is that "female villains only get respect if they're hot". Which she certainly isn't, being an undead Black Knight.
In the relatively new Flash, in-browser game "RPG Shooter: Starwish" 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 is one of the three remaining survivors of Lucerna
This is explicitly referenced in Girl Genius, 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 Pacificators. On one side, TaffeTorbern 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 mistaken for a boy, especially by the Too Dumb to Live 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.
When She Was Bad has a highly feared mob enforcer who goes by the name Coyote. Most people assume the Coyote is male, but she is actually a Perky Female Minion named Rosie. Her employers are pretty much the only ones who know her true identity, since she never leaves witnesses alive.
Twitch Plays Pokémon 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.
We Are Our Avatars: When Michelle took Proto Man's helmet in order to repair him, it turns out that Roll was impersonating Proto Man the whole time.
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.
Sarasim in the Teen Titans episode "Cyborg the Barbarian". Cyborg is her "Bob."
In the 2003 Teenage Mutant Ninja Turtles 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 man strapped to a table and turned into something that looked like Quarry.
The X-Men: Evolution 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 Batman: The Animated Series. 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 Batman Beyond episode "Payback", in which Batman (Terry) faces a dangerous Knight Templar 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. Payback later turns out to be the doctor's young son wearing an armored suit.
In one episode of 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.
In The Flight of Dragons, the 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.
Sponge Bob Square Pants parodied this trope, when Sandy Cheeks took off her diving suit in one episode. 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).
Chris is conflicted over kissing a friend named Sam... Until he finds out she's a girl.
In another episode, 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 old Looney Tunes 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 The Grim Adventures of Billy & Mandy, 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).
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.
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.
Also 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 princess.
One of the main villains of The Condor, 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.
A variation in Kim Possible, during "A Sitch in Time", Rufus 5000 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 5000 answers, "But I don't see her!" Rufus 5000 then reveals the true Supreme One; Shego. Lampshaded of course:
Rufus 5000: 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 a 'guy' thing.
In the G.I. Joe: A Real American Hero 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.
In Ben 10: Omniverse, Kevin is the first person to notice that Khyber's pet whom he adopts after Khyber abandoned it is a female.
In the 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.
Discussed on South Park:Cartman is obsessed with finding out Mysterion's secret identity and begins grilling all the guys at school. Wendy passes by and casually wonders why he assumes Mysterion is a boy at all. Cartman immediately looks shocked and suspicious of Wendy. (Subverted, however, in that Mysterion ultimately turns out to be male.)
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 a baby dragon that is partially hatched, lodged in the obviously female dragon's womb.
In 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 The Secret Show, a villain called Dr. Hypno was eventually revealed as a woman, which shocked even former rival and retired secret agent Zach Meadows. And then they got married.
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.
Another 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.
There was a stagecoach driver in the American West named 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 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, assuming they're male until proven otherwise. This used to be inverted in some parts of Israel (particularly in 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.
My God! It's a Woman, the biography of Australian aviatrix Nancy Bird.
The Science Fiction 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.
J. K. Rowling. Apparently, some people were surprised to learn the real name. This was deliberately invoked by the publisher because their initial target audience was young boys who they felt might be put off by a female author.
Jack Prelutsky's children's poem "The New Kid on the Block" describes the titular new kid as a terrible bully who "likes to fight and picks on all the guys"; and ends with the line, "I don't care for her at all".
Gender Flip: The video "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 another man this whole time. The video was heavily promoted by gay marriage advocates, causing many people to not even realize that the POV character's gender was supposed to be a Twist Ending.
Real Life example: In the 2012 Orange Bowl, a West Virginia player celebrated by tackling the Orange Bowl mascot. This is his reaction upon learning that the mascot was played by a woman.
In 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 Gender-Blender Name or the listener does not have enough context from the sentence to get gender.