-> "But the most wonderful thing about tiggers is... I'm the only one!"
-->--'''[[CaptainObvious Tigger]]''', ''[[Disney/TheManyAdventuresOfWinnieThePooh Winnie the Pooh]]''

Something that applies to many a videogame boss (especially in the case of a GiantSpaceFleaFromNowhere), {{kaiju}} or MonsterOfTheWeek -- you come across a creature that looks unlike anything else you've seen or will see in that work's universe, [[BigLippedAlligatorMoment but only once]].

Creators contemplating for the existence of more of these tends to be a gap in their WorldBuilding, but tends to be a case where the MST3KMantra applies in full force. It would be hard for an ecosystem to support more than one of it, after all, so just enjoy the game.

For LongRunners, this may become a temporary trope, as a family/species and natural habitat may be created for the being in question [[ChekhovsBoomerang at a later time]].

Obviously different from the OneGenderRace as there's only one specimen, and the concept of gender may not even apply. Also different from LastOfHisKind, as that implies the existence of more of the same species in the past, or AKindOfOne, where a whole species is known by the name of its most famous member, who may initially have been this.

Note that a Single Specimen Species is defined as being basically unexplained and therefore EcologicallyImplausible. So the LastOfHisKind can't "become" this, since that includes human survivors of a lost tribe, animals that were wiped out and so forth. However, AKindOfOne may become an example in ''subsequent works'', following the original; in which case it may be a case of CallASmeerpARabbit since the characters have certainly never seen it before, but [[PopCulturalOsmosis the readers have]].

Not to be confused with OnlyYouCanRepopulateMyRace (which is ecologically implausible for [[AdamAndEvePlot entirely different reasons]]).
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!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* [[http://dragonball.wikia.com/wiki/Buyon The Buyon]] from ''Manga/DragonBall'', which could resist a Kamehameha in a relatively early stage of the series, was present only in a "boss tower" surrounded by an ecosystem in which it couldn't survive (FridgeLogic can be an important part of this trope — in this case, how did they bring the creature into the tower, and where from?). No other specimen ever appears again for the whole series, but it's interesting to see what would have happened if invaders had come across others of the same species — if others existed at all.
** In ''Anime/DragonBallZ'', Cell would apply since he's an artificially created being, but only until he makes some offspring of his own. Something similar happens with Majin Buu (also created, but by magic) in the same series until some variations pop up--and in ''Dragon Ball Online'' he later starts splitting himself apart to create an entire new species.
* All the Angels in ''Anime/NeonGenesisEvangelion'' were this. [[spoiler:Averted by the 18th Angel, us - Until the very end that is, when it becomes a single specimen again... then a pair of traumatized teenagers split off.]]
** All the monstrous Angels actually had a common parent, the equally Eldritch Adam. Its ability to breed with Lilith (the other progenitor, this time of humanity) indicates that both are of the same species. By extension, this means that [[spoiler:humans]] are of the same species as the Angels attacking Earth. All this assumes that 'species' has the same parameters for Angels as it does for earthly creatures.
* Both used and subverted in ''Manga/{{Toriko}}''. Many animals are so bizarre you don't expect to see another specimen, but sometimes one will show up.
* In ''Anime/{{Pokemon}}'' many "legendary Pokémon" would count as one of these.
** The [[FanNickname Poké-Gods (i.e. Dialga, Palkia, Giratina, and Arceus)]] are the only truly "one-of-a-kind" Pokémon. Lugia is shown to have a breeding population, and many of the legendary birds (Articuno, Zapdos, and Moltres) and legendary beasts (Raikou, Entei, and Suicune) are shown to have different members of the species encountered by the main heroes during the course of the series. Likewise, there has been shown to be more than one Deoxys in the series, and the Mew in ''Anime/PokemonTheFirstMovie'' is a different Mew from the one in ''Anime/PokemonLucarioAndTheMysteryOfMew''.
** [[Anime/PokemonTheFirstMovie Mewtwo]] was created by humans and was the only member of his species as [[NoPlansNoPrototypeNoBackup his creators were killed]] and all the research describing his creation was destroyed. That is until the [[Anime/PokemonGenesectAndTheLegendAwakened 16th Movie]] introduced a second Mewtwo that makes it a species of two.
** Also, Latios and Latias are shown to be the offspring of another pair of Latios/Latias in ''Anime/PokemonHeroes'', and Shaymin in ''Anime/PokemonGiratinaAndTheSkyWarrior'' is actually part of a group of Shaymin. There also appear to be two different Jirachi in ''Anime/PokemonJirachiWishmaker'' and the ''Best Wishes'' episode "Wish on Jirachi: The Seven Day Miracle." (Although the existence of two Millennium Comets is harder to explain)
*** In the manga however, it keeps the tradition of only-one species with all legendary Pokémon, with the exception of Deoxys
[[/folder]]

[[folder:Comic Book]]
* The concept/cosmic entity Dream from ''ComicBook/TheSandman''. When the protagonist Dream, Morpheus, dies there is a replacement Dream from a child named Daniel. Although Morpheus is definitely dead, Dream isn't. While the new Dream came from Daniel, he is not Daniel. And while the new and old Dream are treated differently by the rest of the cast, they aren't quite considered separate beings. As Abel put it, it's the same concept but a different perspective.
[[/folder]]

[[folder:Film]]
* Franchise/{{Godzilla}} and other more traditional kaiju sometimes are shown to have offspring, so they're right out. However, the viewers see no indication of a Gojiru population from which it might have sprang. The known Godzilla population is this-Godzilla ([[Film/{{Gojira}} 1954]]), Godzilla (Showa), Minya, Godzilla (Heisei), Godzilla Junior, Godzilla Millennium, Godzilla [[Film/GodzillaTokyoSOS SOS]], and [[Film/GodzillaFinalWars Final Wars]] Godzilla. However, thanks to CanonDisContinuity, it's hard to tell if there are any others or of what relation they all are to one another in the first place.
** In the 2014 remake, he is made to be the last survivor of a race of alpha predators.
* ''Film/KingKong'':
** In the original, to their knowledge they never see anything that could possibly breed with it in that island.
** The 2005 Creator/PeterJackson remake kicks this trope out the door, since it shows a lot of bones from Kong's species - he's made out to be the LastOfHisKind.
* ''Film/StarWars'': The Sarlacc and the [[SandWorm Space Worm]], prior to the somewhat dubious explanation for each in the [[AllThereInTheManual Extended Universe]] novels and books.
* Subverted in ''Film/{{Rodan}}''. The eponymous mutated Pteranodons are shown to be a breeding pair.
* The Heisei ''Franchise/{{Gamera}}'' films:
** Averted with the Gyaos. They can reproduce asexually and are soon able to attack in large swarms.
** Likewise, subverted with Gamera himself. At first glace, it seems that he's the only one of his species. Then, during ''[[Film/Gamera3AwakeningOfIrys Awakening of Irys]]'', we see that there were '''thousands''' of Gamera that existed before him, but were all killed out leaving him to be the ''last'' of his kind.
* Gonzo from ''Franchise/TheMuppets'' was this for a while [[spoiler: before being revealed as an alien]], since he himself didn't even know what he was. Invariable he was referred to as something like "a whatever he is".
** In ''WesternAnimation/MuppetBabies'', he's often classified as a "weirdo".
[[/folder]]

[[folder:Literature]]
* The Watcher In the Water in ''Literature/TheLordOfTheRings''. (Probably Tom Bombadil too.)
** It is suggested that the Watcher is one of the "nameless things" Gandalf mentions that live deep, deep below Moria. This one just happened to find its way to the surface somehow.
** Parodied by The Straight Dope [[http://boards.straightdope.com/sdmb/showpost.php?s=4232c53a7ab66a114656ca0264863d5f&p=2506868&postcount=32 here:]]
--->''"The Halflings, cap'n, they will na take the strain"''
--->''"Strider, we've got to get out of this snow. Legolas, did you get a reading on that creature?"''
--->''"Fascinating, Captain. It appears to be an unknown creature that lurks in the pool waiting for passing strangers. EcologicallyImplausible, captain."''
--->''"Do you know what it is?" ... "I believe I said it was unknown, Dr Gimli. Logically, if I knew what it was, then it [[CaptainObvious wouldn't be unknown]]."''
--->''"Cap'n, we're in some sort of temporal warp, stretching and deforming the plot. The snow should take place a day before our encounter with this beastie." ... "Boromir, put on that red armour..."''
** In the ''Literature/{{Mithgar}}'' books, which started as Tolkien fanfic complete with pseudo-Moria and pseudo-Watcher, there is eventually an explanation both for the ecology and how such a huge monster got into the isolated lake - it's a kraken, they're part of a BizarreSexualDimorphism with dragons, and a dragon flew by and dropped it into the lake to annoy the dwarves. [[spoiler: The dwarves manage to kill it by breaking the dam and draining the lake.]]
* The title "character" in ''[[Literature/{{Illuminatus}} The Illuminatus Trilogy: Leviathan]]'' is a gigantic single-celled organism at the bottom of the ocean, a result of the first cell division that just got bigger and bigger while the rest of life on Earth developed into multicellular organisms. [[spoiler:It's actually just a metaphor for the State. Straight out of Thomas Hobbes' article of the same name.]]
* In ''Discworld/TheLastContinent'', the Wizards of Unseen University visit an island populated only with single specimen species. This is because the island is home to the god of evolution, who personally engineers each animal (and tweaks it as it goes along), and is blissfully unaware of things like sexual reproduction.
* Adam in ''Literature/TheBible'' qualified, before Eve entered the picture. {{God}} himself too.
* The Incredibly Deadly Viper in ''Literature/ASeriesOfUnfortunateEvents''
* Tigger from Literature/WinnieThePooh. He gleefully rejoices in it too.
* Marko from ''TheSanguineChronicles'' is a half-vampire, half-werewolf… which for reasons outlined in the story, is supposed to be impossible.
* The Goo in ''Literature/FlukeOrIKnowWhyTheWingedWhaleSings'' is an enormous, unique, single-celled organism much like that from ''Illuminatus'' above, although it's not a metaphor, it's a great huge organism on the bottom of the sea. [[spoiler: It's also the god that whales pray to which ensures there's always plankton. And it does.]]
[[/folder]]

[[folder:Live Action TV]]
* A number of entities and creatures in the various ''Franchise/StarTrek'' series.
** On ''[[Series/StarTrekTheOriginalSeries The Original Series]]''
*** The creature that was Jack The Ripper. An entity that fed on fear and death, who claimed to be as old as time.
*** The Guardian of Forever. While the ruins around it seem to imply that it was artificially created, it claims to have always been. (Or at least to be older than Earth's sun.)
** On ''[[Series/StarTrekTheNextGeneration The Next Generation]]''
*** Ronin is a ghost-like lifeform apparently from Earth that bonds symbiotically with a human female, giving her pleasure in exchange for some kind of sustenance.
*** The "Crystalline Entity" is a space-faring creature that consumes organic matter from entire planets. No other examples of its species were seen (until the MMORPG came out, at least).
** On ''[[Series/StarTrekVoyager Voyager]]''
*** The Telepathic Pitcher Plant, a giant space monster that would MindControl the crews of passing starships to fly into its mouth so it could eat the ship whole.
*** The Nebula Creature (a massive organism that Voyager mistook for a nebula.)
*** Bevvox, the founder of The Think Tank, a huge organism which previously wandered the stars by itself for thousands of years. Unlike some of the others listed here, instead of bragging about how ancient it is, it's apparently sensitive about its age.
* One episode of ''Series/HowIMetYourMother'' had Marshall and Lily discover a small animal living in their apartment that had the characteristics of both a cockroach and a mouse: they dub it a cockamouse. No such creature is ever heard of again after they threw it out the apartment window (don't worry; it can fly).
** The cockamouse turns up in a later episode, in a room in a rundown hotel that Ted stays in for plot-related reasons. He cheerfully reports that it's had babies.
* Many, many [[MonsterOfTheWeek monsters of the week]] on ''Series/TheXFiles'' and ''Series/TheOuterLimits.''
* Averted in ''Series/StargateSG1''. It looks to be a straight example when the Unas is first shown (his name certainly gives the impression). Another doesn't come along until two seasons later, at which point their nature as a species is explained (and Jack {{lampshade|Hanging}}s the confusing name.
[[/folder]]

[[folder:Mythology]]
* Many of Echidna's monstrous children such as Cerberus and the Hydra are these.
* ThePhoenix -- the western one -- was the only member of its species. "As singular as the phoenix" was a common comparison.
* Similarly, there was originally only one {{Pegasus}}, born from the blood of Medusa.
* The Minotaur. Most versions have a bull's head, with horns, hooves instead of feet, hands as hard as horn with a bull's strength in striking, and a taste for raw flesh. It was uncontrollable and had to be imprisoned in Crete's Labyrinth -which makes the pictures of him with the ring in his nose rather odd.[[labelnote:*]]The ring is in the sensitive part of the nose and is used, with a rod and hook, for keeping the bull under control.[[/labelnote]]
* The Chimera, a three-headed female monster that was part goat, part snake, part lion, with a head for each and breathes fire. It terrorized Lycia as some sort of ancient {{Kaiju}} until it was slain by Bellerophon.
[[/folder]]

[[folder:Tabletop RPG]]
* In early editions of ''TabletopGame/DungeonsAndDragons'', any creature with a Frequency of "Unique" was this trope, as there was only one of them. Examples included demon lords, arch devils, deities and the tarrasque.
** The fluff indicated this for the Tarrasque in later editions, as well, with the crossover-relevant proviso that unique means ''per world'', not for the entire multiverse (''TabletopGame/{{Spelljammer}}'' had an apparent exception to that as well -- a world crawling with Tarrasque-like beasts... that are docile lithovores. It is theorised to be the Tarrasque homeworld, and the native state of the being when not exposed to other atmospheres).
[[/folder]]

[[folder:Video Games]]
* There appears to be more legendary Franchise/{{Pokemon}} that are single specimen than the anime does, but it's hard to tell whether most are the only one, period, or just so rare they haven't found a second.
** Those almost certain to be one-of-a-kind include one-off bioengineering experiments [[VideoGame/PokemonRedAndBlue Mewtwo]] and [[VideoGame/PokemonBlackAndWhite Genesect]]; the godlike [[VideoGame/PokemonDiamondAndPearl Arceus and its creations Uxie, Mesprit, Azelf, Dialga, Palkia, and Giratina]] (though Arceus is known to make seconds of the latter three); also godlike [[VideoGame/PokemonRubyAndSapphire Groudon, Kyogre, Rayquaza]]; and results of a unique transformation [[VideoGame/PokemonBlackAndWhite Reshiram, Zekrom, and Kyurem]] (Reshiram and Zekrom [[LiteralSplitPersonality two halves of a great dragon]] according to legend; Kyurem theorized to be the remains of the original).
** There are also a few definite aversions: Latias is stated not to be one-of-a-kind in one Pokédex entry (and its SpearCounterpart Latios would be the same), Deoxys and Diancie come from rare but repeatable mutations, and Manaphy are known to both hatch from eggs and produce more eggs (though their offspring in captivity are Phione and not more Manaphy).
* In ''VideoGame/{{Pikmin}}'', the Puffstool and Smoky Progg are fought only once and do not appear in the sequel. Averted in ''Pikmin 2'' since any boss can be fought again, even if killed the first time.
** The Progg, however is claimed to be a mutant baby Mamuta by the end credits.
* The Nihilanth in ''VideoGame/HalfLife1'' are similar biologically to other Xen creatures (especially the controllers), but apparently the only one of his species. According to WordOfGod the Nihilanth's species was systematically hunted down and exterminated by the Combine until only this one remained. Until Gordon killed it, anyway.
* Forgotten Beasts in ''VideoGame/DwarfFortress'' are [[CaptainObvious forgotten]] remnants from when the gods created a given world. Each one is unique as a result of being procedurally generated, and can vary in terms of limb count, tails, flight, dangerous excretions, and sometimes being made of inorganic things like glass or mist.
** This gets weird when there is no feasible way for them to survive until they reach you. Creatures made of Mist, Fire, Water, and Dirt [[GoodBadBugs are universally killed in one or two hits because the materials they are made of tend to fall apart when attacked; your dwarves tending to punch heads, this causes heads to break apart, killing the creature.]]
* The Thorian in ''Franchise/MassEffect'' was the only known specimen of its species in existence. This is probably a good thing, as it was hostile to most other forms of life and liked to mind-control people through spores. All that's left of it now is its nearly planet-wide root system... hopefully it can't regrow itself from that.
* It's implied that Tails from ''Franchise/SonicTheHedgehog'' is the only multiple-tailed fox on the planet.
* In ''VideoGame/StarcraftII'', two unique Zerg entities appear during the ''Heart of the Swarm'' campaign. Izsha probably doesn't count so much, given she [[WasOnceAMan was mutated from a Terran woman]], but Abathur is a totally unique abomination created by the Overmind itself to serve as the chief geneticist for the Swarm; Abathur even notes during the campaign that it would be difficult, if not impossible, for his geno-structure to be recreated and for more like him to be made.
* Torkscrew in ''VideoGame/MarioAndLuigiDreamTeam''. This boss... is never really explained species wise, and the game itself actually has characters who wonder what the hell it is and whether things like that live in the desert now. Additionally, you could also say this applies to the Zeekeeper, although that's probably due to him being a deity.
[[/folder]]

[[folder:Web Comics]]
* In ''WebComic/TheInexplicableAdventuresOfBob,'' Molly qualified until [[NamesTheSame Dean Martin]] cloned her to make Golly.
[[/folder]]

[[folder:Western Animation]]
* Any Kaiju in ''WesternAnimation/ThePowerpuffGirls''.
* Most imaginary friends in ''WesternAnimation/FostersHomeForImaginaryFriends''.
* Each of the 627 genetic experiments in ''WesternAnimation/LiloAndStitchTheSeries'' and Leroy from ''WesternAnimation/LeroyAndStitch''
* ''WesternAnimation/Ben10AlienForce'': Sugilite, guardian of Petropia, is the only one of his kind, until a sample of his DNA was placed into the Omnitrix, creating Ben's Chromastone form.
* The Hydra and the Sea Serpent in ''WesternAnimation/MyLittlePonyFriendshipIsMagic''. The Hydra lives in a swamp inhabited by tiny frogs within walking distance of Ponyville and is more than eager to chase Twilight Sparkle and her friends, yet never seems to stroll over to munch on the happy little ponies. The Sea Serpent is much more friendly, can talk, and is very ''very'' CampGay, and shouldn't even be able to fit in the tiny river he lives in, let alone find enough food to keep himself going.
[[/folder]]

[[folder:Real Life]]
* Tales of the [[StockNessMonster Loch Ness Monster]]. Unless it actually is a type of aquatic dinosaur, if it exists. That would make it a LastOfHisKind scenario.
* Scientists uncover these all the time. [[FridgeHorror Frighteningly]], it's often unknown if they are the [[LastOfHisKind last of a species]] wiped out by human activity or the tip of an iceberg that is never uncovered because a second specimen is never identified. A rule of thumb regarding species is that common is rare and rare is common, or that there are more species with smaller sample sizes than there are of large known populations.
* Some long-extinct species are known from only one fossil (hence a single specimen), which can make it difficult to know which features were common to the whole species and which were specific to the organism; for example, the specimen may have had a genetic disorder, or may be younger (and hence smaller) than average. Also, even after other fossils are uncovered, the original discovery [[AKindOfOne may be so iconic]] that it is forever tied to the species, especially if the original has a name: far more people know about "Lucy" than about ''Australopithecus afarensis''.
* These examples overlap with LastOfHisKind
** [[http://en.wikipedia.org/wiki/Lonesome_George Lonesome George]], the very last Pinta Island Tortoise.
*** As of 24 June 2012, no longer an example, sad to say. R.I.P., George.
** ''[[http://en.wikipedia.org/wiki/Hyophorbe_amaricaulis Hyophorbe amaricaulis]]'', the Loneliest Palm. This is a species of palm tree with only one known member in the world, in a garden in Mauritius.
** The [[http://en.wikipedia.org/wiki/52-hertz_whale 52-hertz whale]], the Loneliest Whale. Its actual species is unknown, but it has a unique song, and has never gotten a response in the years researchers have been recording it.
* Several animal hybrids exist that have had only one known representative, such as Harjeeven the half-African/half-Asian elephant calf (deceased) born at Chester Zoo. Most such hybrids arise in captivity, as species that interbreed in the wild tend to do so more frequently than this trope demands.
[[/folder]]
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