Ron Moore: Help? Why would I need help writing plots? I just throw a dart at the cast list, and...boom! They're a Cylon! Rinse, repeat, cash the f*cking check. Watch! Sh'boom! Sh'bong! Sh'bing! Cylon. (mockingly) Please help me! This is so hard!
Creating a fictional subcategory that can be applied to any character, treating it as some sort of rarity or shocking twist, and then applying it to most or all of the cast. Possible as a method to create a Meta Origin; its effectiveness/appeal may vary.
The trope name references Tomato Surprise and comes from a set of writer's guidelines distributed circa 1980 by Asimov's Science Fiction magazine, written by its then-editor, George Scithers. The guidelines named the trope and gave as one of the examples hiding the fact that the hero is, in fact, a tomato.
Compare Flock of Wolves, which has the similar "minority is actually majority" premise, but is about loyalty to a group rather than innate characteristics. Also Everyone Is Related, where the category is a family, and Uniqueness Decay. Contrast They Look Like Us Now.
Anime & Manga
- Negima! Magister Negi Magi: Although most of the cast was considered normal at the start of the series (excluding Sayo the ghost and Chachamaru the robot), since then it has been revealed that Yuuna, Misora, Konoka, Hakase, Takamichi, Chao, and the Headmaster were all involved in magic from the beginning, and Evangeline, Mana, Zazie, and Setsuna are demonic. Asuna is practically her own category.
- Early in Ooku (an Alternate History where a plague leaves Japan's adult male population at about a quarter of the women), many families start sending their adult daughters to court in the guise of men as though nothing were wrong. One of them notes that she's far from the only crossdressing woman, and soon after there's no more pretense, with the Royal Harem now consisting of the female shogun's male bodyguards.
- Neon Genesis Evangelion: You know those alien monsters humanity has been fighting throughout the series? Humanity is one of them.
- The superhero team Great Lakes Avengers, renamed themselves The Great Lakes X-Men after finding out that every single one of them was actually an X-Men-style mutant.
- This was also a parody of the then-popular various "X-Titles".
- It's a justified trope in the Marvelverse, mind; most superhero origins are one-in-a-billion freak occurrences, or inventions by 99.999999th-percentile geniuses who for some reason keep their potentially world-changing inventions to themselves. Meanwhile, mutants actually are a notable demographic.
- By the finale of Strangers in Paradise, nearly every female character in the series except Francine turns out to be a current or former Parker Girl.
- In the Doctor Who (Titan) story "The Twist", all of the human inhabitants of the Twist are not descended from the original colonists, who all died in an accident, but humans genetically reconstructed by the sentient descendants of the foxes also carried on the starship.
- When My Little Pony: Friendship Is Magic revealed the existence of shapeshifting changelings, fanfics with the premise "X was secretly a changeling all along" started popping up—enough to become a cliche. Three different authors independently parodied the trend by writing stories where everyone was a changeling all along: Changelings, Changelings Everywhere, Changeling, and Everyone's a Changeling.
Films — Live-Action
- About two-thirds into Identity, it's revealed that every single character at the motel is a personality of Malcolm Rivers, and the whole movie was a plot to kill off his alternate identities, curing his Multiple Personality Disorder.
- In John Carpenter's The Ward, the ghost, and the women she's trying to kill, turn out to be a result of one character's multiple personality disorder.
- Chrestomanci: In Witch Week, the protagonist is secretly a person with innate magical talent in a world where such "witches" are feared and hunted. He learns that one of the other students at the school he attends is also secretly a witch. Then another. And another. Also, some of the teachers. (The deputy principal isn't really a miser, he just has no money because he's a witch and the principal is blackmailing him with the threat of exposure. The principal, unbeknownst to him, is also a witch.) In the end it turns out that, as a result of a supernatural event in the 17th century, everybody in the world is a witch, but they're all hiding it from each other for fear of persecution.
- The main characters of Haruhi Suzumiya are an everyman-type and his best friend who start a club to search for evidence of the supernatural. They recruit three classmates, who reveal to the everyman that they are in fact a psychic, an alien-controlled robot and a time-traveler, and the best friend is a Reality Warper but doesn't know it.
- The Discworld novel Monstrous Regiment is about a Sweet Polly Oliver going off to war. Gradually over the course of the story, she discovers that more and more of her comrades are also women, some in more convincing disguises than others. All of them, in fact, including the troll. Even the bluff old Sergeant Rock, who also happens to be aware that a good third of the high command are women in disguise, along with Nuggan-knows how many of the troops. The country has been at war for so long that all the men have simply been killed off.
- In Girls with Sharp Sticks, the main character discovers that she's actually an Artificial Human being groomed into the perfect Robotic Spouse. Then it turns out that so is everyone else at her school.
- The second Battlestar Galactica made nearly half the cast Cylon infiltators. Although there was plenty of evidence to suggest that Tyrol was one, and even that Tigh OR Ellen was one — which necessitates the other. Not to mention precedent of sleeper agents. This was not planned out in advance, however, but rather a hasty improvisation by the writers.
- Buffy the Vampire Slayer: At the start of the show, only Buffy was anything other than a normal human, but by the end, several supernatural beings had joined their group, and almost everyone had learned how to practice magic.
- Doctor Who: In "Full Circle", the inhabitants of the Starliner are not descendants of the original crew and passengers, but descendants of indigenous life-forms who massacred them and then took on their forms.
- Dollhouse: Lubov is a doll! Mellie is a doll! Saunders is a doll! Season 2 brings even more.
- The Good Place is about an amoral person who thinks she's been mistakenly sent to Heaven after death and tries to blend in. Then it turns out she's actually in Hell, and everyone around her is either in the same situation or a demon stringing them along.
- In the Star Trek: Deep Space Nine episode "Shadowplay", Odo and Dax beam down to a village and investigate the disappearance of a number of villagers. It turns out the village and its inhabitants are holograms - news which they take surprisingly well - and the device that powers them is wearing down. Dax is able to fix the device, but not before discovering that the village elder is a flesh-and-blood life form and the creator of everyone and everything around him. He doesn't want his fellow villagers to know he's different from them and responsible for their existence; Dax and Odo agree not to tell them.
- True Blood: The folks with supernatural powers will soon outnumber the normal people in Bon Temps.
- V (2009): Seems like every third character is secretly a V sleeper. Two of Erica's FBI partners were Visitors—not to mention her obstetrician.
- John Finnemore's Souvenir Programme: Spoofed into oblivion in a parody of a murder mystery, where everyone turns out to be someone (or something) else in disguise. The thief everyone's looking for is actually the narrator himself.
- Dungeons & Dragons and similar High Fantasy campaigns can fall into this if the GM puts a Ban on Magic in their setting, or just tries to make magic more rare. Due to the high percentage of magic-using character classes, your party will almost inevitably be majority wielders of "rare" and "hidden" sorceries.
- Part of the point of Paranoia is that player characters are dystopian special forces charged with exterminating mutants and secret society conspirators. The players, but not their characters, are fully aware that everyone in this dystopia is a conspirator and mutant.
- All the playable protagonists of 13 Sentinels: Aegis Rim, and two other supporting characters, are clones being raised in People Jars Inside a Computer System after humanity was wiped out. Every other character in the present is an AI—including several digitized copies of previous clones.
- Right near the end of Assassin's Creed II, you find out that every helpful adult save your mother and Leonardo DiVinci is an Assassin that's been helping you become one of them.
- Played for laughs in the second Earthworm Jim: The ending reveals that Jim, Princess What's-Her-Name, and Psy-Crow were all cows in disguise.
- Fallout 4: Virgil is an Institute scientist who turned himself from a human into a Super Mutant. Several characters express strong surprise and confusion on how that's possible. Later, you learn that the entire species of Super Mutants are ex-humans whom the Institute altered that way.
- From Kingdom Hearts II onwards, almost every single mysterious character manages to be a form of Sora, no matter how illogical or unlikely it seems. The only ones who aren't are the ones who actually turn out to be a form of Xehanort.
- No Man's Sky reveals various characters and game elements as pawns of the mysterious Atlas. Then you learn that the universe is a computer simulation (inside the story, not just as a video game) and Atlas is the computer that literally controls everything.
- Subtle one in Silent Hill 2: all male character models in game who aren't Eddie are James. Pyramid Head, the corpses all over the place, the prisoners, the Lying Figures, all of them. Similarly, most female models are Mary.
- Xenoblade Chronicles X quickly follows up a surprise Robotic Reveal on the protagonist by revealing that all the "humans" in New LA are Ridiculously Human Robots, and that the protagonist, by virtue of having no memory, was literally the only one who didn't know this from the start.
- In It's Walky!, several cast members are revealed to be former abductees.
- Parodied in Futurama, with an episode of Calculon's soap opera where characters keep announcing they have Laser-Guided Amnesia to the point that it starts to get annoying. "Is there anybody here who doesn't have amnesia?!"
- Neo Yokio: Near the end of Charles' story in "Pink Christmas", Kaz reads Aunt Angelique's memoir and discovers that his demon-hunting Magistocrat family actually has demonic ancestry. Later, the Great Demon confirms this and takes it a step further: not only is the Kaan family descended from demons but every single Magistocratic family is also descended from a group of demons who used their powers to hunt other demons in exchange for money and social standing, making every demon hunter a demon in disguise.