- Alterien series. The Alteriens, aka homo alteris, are this. In their concealed form they look like any normal human with the usual exception of being highly attractive. As this particular trait can sometimes make them stick out in situations they may want to be more inconspicuous, they can shapeshift to look like a less attractive, more average-looking human at any time. Oberon and the other Alteriens of the first group were completely unaware of true nature of their "human" bodies until the Sisters of Orion reveal it to them later on in the series (The Orion Directive).
- Robert Rankin shamelessly lampshades this in one of his stories (Armageddon, the Musical) where it is advanced as proof that there is a God who designs dominant species in his own image. "As any Science Fiction fan knows, the basic human shape, Head at the top, two feet at the bottom, wedding tackle about halfway down, is the standard for intelligent life the universe over. They often speak good English with a noticeable American accent, too. Facts that should serve up friend Atheist with a workload of eggs, faces for the use of."
- Angels in The Bible are an interesting take on this. Usually they look near indistinguishable from humans. The ones who announce Jesus resurrection are a good example of this being described simply as men in white robes. On the other hand some angels can be a lot stranger.
- In one Discworld book (though it was referring to gods, the spirit's the same), it's mentioned that if you ask someone to come up with an alien-looking being, it would basically be a man in an animal mask.
- Older Than Television: Edgar Rice Burroughs did this all over the place.
- Starting back in 1912 with A Princess of Mars. Everybody on Mars except the Green men looked human, but hotter, and have much longer lifespans. The earth born hero John Carter and his Martian Princess wife have two kids, despite massive biological differences including Martians being oviparous.
- In the Amtor series, the people of Vepaja, a nation on Venus, slightly resemble Middle-Easterns on Earth.
- This doesn't even begin to cover some of the wild biology that shows up in The Land That Time Forgot stories.
- The ecosystem of Pellucidar is supposedly entirely convergent evolution from the outer surface of Earth, except without the asteroid-induced mass extinctions. Resulting in several sapient species ranging from pterosaur-descended Mahars to humans, though at least one tribe of humans are known to be descendants of Barbary corsairs who sailed through a passage at the North Pole to Pellucidar.
- The Takisians of the Wild Cards series. In fact, that's what leads to the entire plot of the series; the Takisians note how biologically similar they are to humans, believe they must be the descendants of a "lost colony," and drop the wild card virus on Earth to test out its purpose as a biological weapon. Humans and Takisians can even have children together.
- The various biological species of The Culture are mostly human-looking, although they have various additional internal glands and bits. Given the degree of casual genetic modification in the universe though, it's anyone's guess as to whether they were all always like that.
- Use of Weapons:
- Shias Engin asks Zakalwe "I know that all the outworlders aren't humanoid, but a lot are. How come?". Zakalwe replies jokingly that it is the universe's way of getting rid of alcohol.
- Some of them are human, a result of the Culture grabbing some of them to spread out across the universe.
- The essay A Few Notes on The Culture deliberately sidesteps the issue:
Now, in all the above, there are two untold stories implicit. One is the history of the Culture's formation, which was a lot less easy and more troubled than its later demeanour might lead one to expect, and the other is the story which answers the question; why were there all those so-similar humanoid species scattered around the galaxy in the first place?
Each story is too complicated to relate here.
- Played with somewhat, in that while the Culture's main species are called "Human", they're not quite what we think of as "Human"; A character in The State Of The Art needs cosmetic surgery to fit in on Earth.
- It's also implied that while human is a recurring body plan, it's not the only one — the various races of humanoid are called "pan-human", but a race of bouncing monopods are referred to as a "pan-hopper" species in Surface Detail.
An interesting variation on First Contact occurs in The Algebraist
, another of Iain M. Banks's sci-fi novels. It is mentioned that humanity - (perhaps just human genetic material) - was transplanted from Earth to a number of nearby worlds in 4051 BC
. These humans were raised in an interstellar culture while Earth itself was declared off-limits. Result; by the time Earth discovered interstellar travel, Human Aliens
, or aHumans outnumbered the remaining humans or rHumans by an order of magnitude. First Contact was less We Come in Peace Shoot to Kill
than What Kept You? As a method of preventing every First Contact boondoggle ever theorized, it worked. It also annihilated all terrestrial human culture.
Encyclopedia Exposita: Prepping. A very long-established practice, used lately by the Culmina amongst others, is to take a few examples of a pre-civilised species from their home world (usually in clonoclastic or embryonic form) and make them subject species/slaves/mercenaries/mentored. So that when the people from their home world finally assume the Galactic stage, they are not the most civilised/advanced of their kind (often they're not even the most numerous grouping of their kind). Species so treated are expected to feel an obligation to their so-called mentors (who will also generally claim to have diverted comets or otherwise prevented catastrophes in the interim, whether they have or not). This practice has been banned in the past when pan-Galactic laws (see Galactic Council) have been upheld but tends to reappear in less civilised times. Practice variously referred to as Prepping, Lifting or Aggressive Mentoring. Local-relevant terminology: aHuman & rHuman (advanced and remainder Human).
- In Ursula K. Le Guin's Hainish Cycle, this is because all the humanoid races are spawned by a precursor race from the planet Hain (including the humans of Earth). Despite a common ancestry, they do not all look like us. Some of the differences are subtle: some are shorter, some are hairier, some are green-tinted. Some of the differences are profound enough to qualify as a Human Subspecies, as in the case of a people who are hermaphrodites.
- In James Patterson's The Dangerous Days of Daniel X, the aliens on Daniel's home world, Alpar Nok, look exactly like humans. The planet even looks like Earth.
- From the Kadingir series: The Ziti are genetically identical to humans, despite coming from a different world. Many have crossed dimensions into Earth throughout history, so much so that they even have their own government Hidden in Plain Sight posing as a Mega-Corp, the Kadingir Corporation.
- In the Perry Rhodan universe, the ancestors of the most prominent 'human alien' races of our galaxy actually came from Earth. (Extra irony points for one of those species later coming back and, quite unaware, claiming 'Larsaf III' as a colony of their own for a brief time.) Humanoid life in general seems to have some common ancestors in the distant cosmic past, and can also be partially justified by the fact that Sufficiently Advanced Aliens have been known to meddle in the evolution business as well.
- Justified in C. S. Lewis's Space Trilogy, whose premise is that The Bible is true: ever since The Creator became a man, the human form became His favorite, so any intelligent beings created after Christ's time will also have human form. So while Mars (which is older than Earth) has several races of sapient non-humans, Venus (which is so new it is still in its "Eden" phase) has green humans.
- InThe Chronicles of Narnia:
- God in this series has created earthly animals on other worlds. This results in such things as Bear Aliens and Mouse Aliens.
- The beavers in The Lion, the Witch, and the Wardrobe claim the Witch, Jadis, was descended from Lilith, which just raises further questions. Of course, they aren't exactly experts on Jewish apocrypha.
- There is also the claim that she is descended from the Djinn on one side of her family, and the Giants on the other, and to have no human blood at all. One of the themes in the books is that being that look like humans but aren't are, invariably, wrong in ways that make them inimical to humans. This is not her true heritage so much as Malicious Slander but Jadis claims to be an Earth human, which is equally untrue.
- The truth is revealed in The Magician's Nephew that Jadis is the last member of a human looking but nonhuman species from a third world separate from earth and Narnia making her a straight example of this trope. She fled to Narnia because her world was rendered an empty ruin by her magic.
- The Noon Universe novels of the Strugatsky Brothers feature a lot of Planet of Hats Human Aliens civilizations, though their cultural, technological and historical development is rarely 100 % identical to that of the Terrans. Among the most inventive examples are the people of the planet Saraksh, whose entire philosophical and religious system has been heavily influenced by the immense optical refraction phenomenon present in the atmosphere of their homeworld. From the surface it looks like the horizon is above the observer, which makes the Sarakshans think that they actually live inside a hollow cave in an endless piece of rock, rather than on a round planet floating in space. They call all who claim otherwise "Massaraksh" ("of the world inside-out"), a term which is also an Unusual Euphemism for "insane".
- Enchantress from the Stars has all the alien civilizations be different types of humans to make it ambiguous which civilization is Earth. The Torisians of its sequel, The Far Side of Evil, are also pretty human.
- Justified in Sergey Lukyanenko's A Lord from Planet Earth trilogy, where all races in the Milky Way (except humans) have been seeded by a mysterious precursor race. Played straight with Human Aliens from a faraway galaxy.
- Thomas in The Man Who Fell to Earth.
- In Sergey Volnov's Army of the Sun trilogy, there are three alien races who are dead ringers for three of the major human "sub-races" (the term used in the books): whites, blacks, and Asians. Nobody knows why that is the case, although there are plenty of other humanoid races. The leading theory is that they have been transplanted to other planets from Earth by Precursors. This theory is partially supported by several ancient records of the "Asian" race that look eerily similar to Ancient Chinese. To top it off, the name of their legendary ancient leader is very similar to "Genghis Khan". In any case, during the centuries of galactic domination of the EarthStella Empire, these three races were shown preferential treatment due to their, at least external, similarity to humans. After the aliens rebelled (justified, as Imperial humans were bastards), they killed off many humans and enslaved many others. Those who survived and were not enslaved are still treated as second-class citizens (if that). As such, most traveling humans tend to pass themselves off as members of one of these human-like races, as aliens have no beef with them.
- This is the whole point of Zenna Henderson's The People. They may be from another world and have paranormal abilities, but they look exactly like us. (In one story, "Deluge", there's a hint that they may have changed some to match Earth's environment.)
- The Elyins and the Kin in Geary Gravel's 1984 novel The Alchemists.
- Parodied in The Star Diaries by Stanisław Lem, where a group of Starfish Aliens living on an extremely hot planet discuss a possibility of an intelligent species living in a lower temperature; the oldest one explains that the existence of such creatures is impossible, and any other sapient species must be exactly like them. While Lem used the trope in comedic works, he criticized its use in serious ones.
- The people of Ginen in The Shadow Speaker look like black Africans.
- In Alan Dean Foster's Humanx Commonwealth novels, we meet the Pitar, a race that by chance resembles beautiful, perfect humans (albeit with some slightly odd hair and eye colors in the mix).
- Played almost completely straight in Mikhail Akhmanov's Arrivals from the Dark series. While there are some Starfish Aliens and Lizard Folk, most races are of humanoid nature and some are even capable of interbreeding with humans (although this is a rare case). Several are sexually compatible but are not capable of producing offspring together. There is also a race of Space Elves who are specifically referred to as "pseudo-humanoids", as they have 4 sexes and reproduce telepathically. It should be noted that the Lizard Folk still have a basically humanoid shape with the only addition being a tail. However, they are hermaphrodites. The Trevelyan's Mission series, taking place in the same 'verse but much later, introduces other humanoid races, mentioning hundreds of others that have been found in-between the series, most of which are on primitive development levels.
- In The Clan Chronicles by Julie E. Czerneda, the only way you'd know a mated adult female Clan from a human is because their hair has a mind of its own. Men and unmated women look exactly like humans.
- In Adaptation by Malinda Lo, the Imria look exactly like humans but have biological differences such as the ability to heal quickly.
- In Wen Spencer's Ukiah Oregon series most of the Ontongard and Pack are indistinguishable from humans unless they're injured, because they are a virus that took over a human, and they look like their host.
- In the science fiction novel Nation of the Third Eye by K.K. Savage, there are both "good" and "bad" human aliens. The "good" ones are similiar to the Nordics in UFO lore, while some of the negative aliens used to be human and transformed somewhat as they entered a higher dimension.
- Archvillain: Mike, although even he doesn't know it, being an Amnesiac Hero. Only Kyle saw him beam down from space. Subverted as of book three: Mike's not an alien, he's an artificial human created by Future!Kyle and sent back to help his past self.
- The History of the Galaxy features a number of different alien races, including Insectoid Aliens, Starfish Aliens, and even Energy Beings. It does, however, feature two humanoid races: the billion-year-old Emulotti and the 3-million-year-old Harammins (they're blue, though).
- In Alan Mendelsohn, the Boy from Mars, Martians are identified by wearing checkerd sweaters and black-and-white polo shoes, but otherwise look like humans. Turns out Alan Mendelsohn, who looks like a normal boy, really is from Mars. Also the Nafsulians Manny, Moe, and Jack, who just look like short men.
- In Solar Warden, the first alien race to contact the US look like the stereotypical "Nordic aliens": tall, incredibly beautiful, white-haired, with eyes slightly larger than normal. They offer to share their tech in exchange for the US to disarm all their nukes. Naturally, since they show up at the height of the Cold War, Eisenhower refuses. They later turn out to be humans from the distant future (about 11,000 years), who have colonized their past. This makes their concern over nukes understandable: if modern-day humans nuke themselves to extinction, the "Nordics" will disappear as well.
- The aliens in Young Wizards generally go for a more Humanoid or Starfish design, but the inhabitants of the planet Wellakh such as Roshaun and his family look completely human. At one point Roshaun insists that he's the human and the Earth characters are the humanoids, but it's not made clear if there's an actual relationship or if he's just blustering.
- Isaac Asimov's "The Watery Place": The aliens from Venus were careful to assume human shapes. Unfortunately, this meant the person they chose to meet for First Contact thought they were humans playing around with him, and he was already annoyed from doing his taxes, so he told them to "Get the hell out of here".