Starfish Aliens / Literature

Starfish Aliens in literature.

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A

• Most of the aliens in Mark Crilley's Akiko books are simply cartoonish humanoids, but one of the recurring characters, Poog, is a purple-skinned floating head with extremely powerful Psychic Powers.
• Iain Banks' The Algebraist has aliens that resemble tumbleweed, pure energy beings, sentient nebulae, and a several species of creatures that live in the atmospheres of gas giants, some living for billions of years.
• The Jan in Alien in a Small Town are trilaterally symmetrical silicon based burrowers who communicate by projecting 3D sonar images at each other. They have three sexes, the child-carrying one of which, the Matriarchs, grow into giant sentient sessile mountains. They're also compulsively honest. They have a cultural tradition against heavy body modification or any technology use that they believe would encourage decadence.
  • The Arachne, meanwhile, are an amalgam of many alien races, who have modified their bodies beyond recognition. They're cyborgs who tend to favor insect-like shapes, the better to move around in zero gravity. They prefer asteroids and space stations to planets' surfaces. They travel throughout space, encouraging other races to cyborgize themselves to be just like the Arachne. Notably, because they can edit their own brains at will, their individual personalities and identities are always in flux, and they tend to have very short attention spans.
• Animorphs:
  • The Taxxons are essentially gigantic worms with a zillion rings of teeth, extra-long prehensile tongues, and a buttload of claws and legs. Their mouth structure makes it impossible to speak the common language of the galaxy, and they are beholden to an uncontrollable hunger that will result in them eating even themselves if they are injured. They are played in a more sympathetic light after Ax and Tobias both morph into them at one point, and ally with Jake as part of his final strike against the Yeerks in exchange for morphing technology in order to trap themselves in forms that aren't enslaved by their hunger: large, Amazonian snakes.
  • The Yeerks, a race of parasitic slugs that burrow into the ear of their hosts to infest and take over their brains, feed off of energy from their home sun, and reproduce though some sort of fusion/fission ritual that kills all three of the parents. In their natural state they're completely helpless and have no form of language besides adorable squeaks, despite being intelligent and entirely sentient.
  • The Andalites are blue centaur-like beings that have no mouths, have scythe-like blades on their tails, eat by absorbing food through their hooves, speak using telepathy, have four eyes, can see in multiple spectrums, have incredibly precise internal body clocks, and have three hearts.
  • The vast majority of the alien species in Animorphs. Leerans (psychic giant yellow frogs with 4 tentacles instead of arms who can easily survive half of their brains being removed and go on to regrow them), Hork-Bajir (7 foot tall 'walking salad shooters' with blades everywhere who eat tree bark), the Arn (a race of hyper-intelligent things that look sort of like squirrels, with gemstone eyes and wings), the Helmacrons (each about 1/16 of an inch high, who have 4 legs and triangular heads and whose brains are absorbed by the rest of the species when they die)...
  • Even their version of The Greys is bizarre. Called the Skrit Na, the species has a weird life cycle: first you get a Skrit, which is basically a giant cockroach, but then it goes into a cocoon, dies, and a "Grey"-type Na emerges from its corpse. Also, for the record, Na walk on all fours normally, but apparently humans sometimes see them standing on their hind legs and got confused. (Based on Andalites' comments, humans seem to be the only tailless species that makes bipedalism a habit.)
• Isaac Asimov:
  • "Does a Bee Care?": Kane has Psychic Powers and a strange life-cycle, where he initially appears as a member of the most intelligent species on the planet he is on, inspires them to reach space in a rocket, then transforms into a Space Whale.
  • The Gods Themselves is unusual for an Asimov book in that it does feature aliens, instead of just humans and robots. There are two species, living together on a planet in a parallel universe, known as hard ones and soft ones. Neither are physically described in much detail, but the soft ones are apparently amorphous or gas-like, have three genders, and appear to be photosynthetic. The hard ones are three soft ones united during sex, acting as an independent being. Asimov joked he created them because someone complained there wasn't enough sex in his stories, so he made three.
  • "Green Patches": All of the aliens encountered here share a Hive Mind which can design parts of itself to look like anything, including pieces of wire, and which is desperate to incorporate life on Earth into itself.
  • Other Asimov books include: four legged herbivorous aliens which need hydrogen cyanide in the air they breathe, and who cannot understand marriage ("Hostess"); sulfur based life forms which cannot understand how humans can have more than one government ("In a Good Cause—"); chlorine based creatures which evolved from something like insects, who cannot understand how a group of humans found together can be anything but a social group connected more deeply than a family ("C-Chute"); tentacle horrors from a dying planet who are seriously disturbed by the fact that humans can feel emotional connection to their children ("The Deep"); bug eyed monsters who cannot understand the idea of sexual reproduction ("What is This Thing Called Love?").
• Isaac Asimov and Janet Asimov's Norby Finds a Villain: The Biguglies and the Twintas are the most unusual alien species by Asimov. They have a tree-like shape, skin a pale peach (when healthy), eight stubby (root-like) legs, and ten palm leaf-like appendages extending from the top. The Biguglies have a strong cultural divide that has had linguistic effects as well; a pirate branch that is rebelling against the M.C. (Master Cult). Both species have enough latent Psychic Powers that they can utilize some Touch Telepathy, but the M.C. has also developed the ability to cause pain at a distance.

B

• The Bible describes angels as having bizarre appearances or as being easily mistaken for humans, never anywhere in between. The former cases (eye covered wheels being among the most mundane) are apparently horrific, such that they usually introduce themselves with "Be not afraid" when delivering messages from God to humanity. Some examples of descriptions of angels include having hundreds of hands along with multiple layers of heads, speaking fire, talking winds, "amber/electrum coloured" lights, or beings so bright they have to be covered with multiple pairs of wings to prevent Earthly onlookers from spontaneously combusting from their mere presence.
• The Black Cloud by Fred Hoyle is about a sentient nebula-sized entity made of ionized gas.
• The scramblers in Peter Watts' Blindsight are starfish-shaped, with a reproduction cycle inspired by jellyfish (not surprisingly, Watts is a marine biologist). Their metabolism is similar to that used by anaerobic bacteria (except part of it involves quantum tunneling), they have no DNA, and for the best part? They're extremely intelligent, but not self-aware. The sequel reveals that they effectively have no consistent biochemistry or biology at all, and can perfectly design entire new forms of life for an environment in an instant. "They" is a somewhat misleading pronoun, since the human characters wonder, but never find out, whether a scrambler can even be considered an "organism" by conventional Earth definitions at all.
• In Borgel, Arnold the Amporphoid Fleshopod is an alien who works at an interdimensional root beer stand. He's described as a nauseating pink amorphous blob covered in slime and tiny tentacles.

C

• Cakes in Space has the Poglites, which are a kid-sized tube with tentacles all over their bodies, and whos eyes shoot up from the tops of their torsos stalks.
• In Robert J. Sawyer's Calculating God, the first alien met by the main character is a big spider-sphere thing. That alien also takes a few shots at the Rubber-Forehead Aliens on Star Trek, when he is being introduced to human culture.
• Jack Chalker's works:
  • Well World: The series numerous beings ranging from those that look like Mix-and-Match Critters (the last set of creators ran out of ideas and cribbed from each other), to the totally alien. The creators of the Universe resembled giant human hearts with tentacles. The Dreel are the Hive Mind of a sentient disease. The North Zone species... are far weirder than that.
  • The colorful collection of aliens from his Quintara Marathon novels, particularly an actual race of Starfish Aliens, the Durquist.
  • Chalker also has fun with technically non-alien post-humans in the Rings Of The Masters series. A Skynet-like AI has conquered humanity and used genetically modified humans to colonize the galaxy. Even though they are technically human, some of them get very weird, including elk- or cattle-like people that grow horns and become quadrupedal when pregnant to protect their stomachs.
• Chanur Novels:
  • The T'ca are giant snake-worms with five-part radial symmetry. They speak in "sentences" which consist of a rectangle of words five columns across and an arbitrary number of rows down. The same "sentence" can be read horizontally, vertically, and diagonally, with all three readings be equally valid at the same time. This is because they have five brains; the relation between words on the matrix seems to represent the interaction between their brains to create a unitary consciousness.
  • The Chi are hyperactive bundles of neon-yellow sticks.
  • The Knnn are snarls of black hair mounted on spider legs. None of the oxygen breathing aliens have figured out even the tiniest portion of their language, forcing them to use the T'ca as translators. Not that having translators seems to be much help, since the Knnn are so alien that they have yet to be made to understand such simple concepts as "you're going the wrong way down a one-way street". They used to force their way onto dock and take what they wanted; through painstaking negotiations with t'ca intermediators, the concept of 'trade' was conveyed to them. Now they force their way onto dock, take what they want, and leave some other randomly chosen item behind. Maybe the highest-stakes concern of the series’ savvier characters is the worry that someone will provoke the knnn into a war that neither side could ever communicate well enough to stop.
• The Vord in Codex Alera are, for all intents and purposes, the Zerg from StarCraft, which are described below. Their Hive Queen's attempts to look human mostly just succeed in making their totally alien nature that much more obvious.
• Ben Jeapes' Commonwealth trilogy has the First Breed, dubbed the Rusties - four-legged aliens with tentacles near their mouths. Their language sounds like someone being strangled, so they use translators instead. Untranslated Rusties Language has the emotion in square brackets first, then the sentence in double triangle-brackets. [Explanatory] <<Like This.>> They have no imagination - they were raised from primitive cattle beings by the Ones Who Command, who treated them as labour and cannon fodder. The Ones Who Command accidentally sterilized themselves with a virus, and now only the Rusties are left. They have weird ideas about leadership.
  • The Xenocide Mission has what are known by humanity as XCs, short for "Xenocide" as there used to be another species in their home system, but as soon as they discovered their existence they nuked the planet to hell. They have four arms and two legs, can share memories by cutting off "shareberries" that grow from the back of their necks and eating them, and hibernate for half the year after which they temporarily lose their sentience until they kill and eat something. For obvious reasons the Rusties crossed them off their list of potential replacement Ones Who Command. Then the protagonists meet remnants of the neighboring species and discover that they telepathically drain sentience from XCs, when their planets came close to one another the XCs would fight brutal wars with one another, the xenocide was in self defense.
• Frank Herbert's ConSentiency series have the Taprisots (sentient telepathic logs which function as a communication system), the Gowachi (semi-humanoid frogs with a legal system so complex it literally defies description), the Wreaves (semi-insectoid humanoids who take insults very personally), the Pan Spechi (who actually live through five different bodies, one at a time) and the Caleban (vast and massively powerful aliens that appear as sentient stars, and it is strongly suggested that every star in the universe is the visual manifestation of a Caleban).
• Bruce Coville loves these. They often have Starfish Languages and Bizarre Alien Sexes as well.
  • The My Teacher Is an Alien series has a tone, including: a ship's captain who is made of crystals, a shadowy-looking creature that communicates by reflecting light from its body, a cucumber-like creature that communicates by popping pimples on its body, a doctor who looks like a crocodile ("Croc Doc"), etc.
  • The Rod Allbright Alien Adventures series has Tar Gibbons (member of a multi-gendered species), Phil the Plant, and Edgar/Seymour (member of a symbiont species which splits into two bodies as part of its life cycle). On the psychological side, Captain Grakker uses a computerized implant to experience moods.
• The characters of The Crucible of Time are a species of intelligent fungoids.
• Many of the Cthulhu Mythos creatures were, basically, aliens so alien to human comprehension that they became almost mind-snapping by default. Some really were deity-level beings, but others were recognizably just aliens, with cultures and societies akin to humans, just... really not. H. P. Lovecraft, a notorious xenophobe, tended to play on the assumption that human sanity isn't strong enough to deal with confronting creatures from other worlds or dimensions.
  • Elder Things from At the Mountains of Madness are literal starfish aliens with them literally having Radial symmetry based on five. They resemble a barrel or sea cucumber with five staves each with a tentacle at the centre, and in between these staves are wings that also serve as solar sails. On one (oral) end is a head resembling, you guessed it, a starfish, while on the other (aboral) end are five arms for locomotion. They breathe carbon dioxide and reproduce by spores, leading the scientists to think they are both plants and animals at the same time. However, biology aside, they are very human, forming familial units, decorating their homes with obvious (if strange) artworks, and defending their family members with what can only be described as murderous rage. They even won a war against Cthulhu, and essentially created all carbon-based life on Earth. The Shoggoths, their Servant Race, are amoebae composed of stem cells that can form into eyes, mouths and tentacles at will, and the cause of their extinction.
  • The Mi-Go from "The Whisperer in Darkness" are bat-winged multi-limbed fungus-crustaceans with wings that can fly through the "aether" (the now-discredited substance that makes up space).
  • In "The Shadow Out of Time", Yithians are usually depicted wearing — and reproducing in — the bodies of towering, trumpet-shaped tripod beings that already lived on Earth when they immigrated via mass mind-swap. However, like Elder Things their culture is rather human and comprehensible - they have a sense of ethics and fairness, however flawed it might be; parents raise their children, they have laws and criminals etc.
  • The Flying Polyps, historical enemies of The Great Race of Yith, are something of a species of Eldritch Abominations. They come down on planets in order to feed, and are described as having "temporary lapses in visibility" by virtue of not being wholly material. They're also Nigh-Invulnerable to physical harm; the Yithians defeated them with energy weapons. Yith find their minds incomprehensible. As for the Star Spawn, the fact that they are merely slightly scaled-down versions of bona fide Eldritch Abomination Cthulhu speaks volumes about their abomination status.
  • Of all of them, only the Elder Things and the Yithians are made of "ordinary" matter; the Polyps aren't fully visible, the Mi-Go don't show up on photographic film and Cthulhu and his ilk are capable of quickly regenerating from any sort of damage.
  • The most extreme of these would be the eponymous "colour" from "The Colour Out of Space", an extraterrestrial so alien that nobody realized that it was alive until it finally departed.
• The Culture Series, also by Iain Banks, has a lot of pan-human species but, aside from that, features:
  • The Affront - a floating, bulbous mass about two metres in diameter, which hangs from a frilled buoyant gas sac one to five metres in diameter, with a set of tentacles, eyestalks and beaks. Their name is an insult given by another species after their diplomats have been eaten, which they have been using as a sign of pride. Their society has been described as a "never-ending holocaust of pain and misery". Masters of genetic engineering, they mainly use it to make their preferred prey and slave species experience constant pain and fear, and one of the only changes they made to themselves is making sex for their females excruciatingly painful.
  • Flekke are aquatic, elliptical in shape, dark and glistening, with fringing or tentacles at either ends.
  • Idirans are a tripodal species that evolved in extremely harsh conditions, essentially the top monster on a planet full of monsters, protected by keratinous body armor, which becomes even more impervious to damage after they go through their short fertile hermaphrodite stage. They're also one of only species known to be biologically immortal, which leads to them believing they're the only beings that have immortal souls as well, and treating other races accordingly.
  • The Homomda are tripedal as well, but fully trilateral, resembling pyramids in shape.
  • Jhlupe are green, soft-shelled crabs with twelve spindly legs and three eyestalks.
  • Morthanveld are aquatic spiny spheres that communicate through color change and chemicals, and one of the most technologically advanced species in the (three-dimensional) universe.
  • Nariscene are six-limbed insects that communicate partially through pheromones. They select the best mate for the Queen (that dies in the process) every generation through very rigorous exams, and despite inherent militancy eliminated all forms of war from their society, which they live vicariously through others by engineering conflicts and then enjoying the spectacle through their microscopic cameras.
  • Nauptre look like human-sized fruit bats who abhor communicating with other aliens and do it solely through their intelligent machines.
  • Oct have ovoid bodies the size of a human child's torso with eight broken-looking triple jointed spindly limbs protruding out of it asymmetrically and proudly claim to be the inheritors of a Precursor species, which makes other species treat them with disdain since it is demonstrably false.
  • Pavuleans are quadrupedal sapient herd animals with every aspect of their culture reflecting their evolutionary history: they abhor heights so their skyscrapers resemble gently sloping ziggurats, they prefer to make all decisions democratically instead of offloading optimal solutions to machines, and they maintain a virtual "hell" afterlife with demons that resemble their exterminated predator species.

D

• Some of the stories on Daily Science Fiction feature this:
  • The short story "Epinikion" by Desmond Warzel features the Squids, militaristic cephalopod-like aliens with unusual funerary rituals and natural weaponry that spells a hideous end for anyone who loses to them in close combat.
  • "Zala" features a highly advanced civilisation where at least two alien species are in a symbiotic relationship, and where they approach mathematics and logic differently to humans.
• The Creapii in The Dark Side of the Sun, which are "sexless, octopoid", need a lot of heat to survive, and travel around in small egg-shaped exoskeletons when they want to interact with humans, which they're good at. And a rather hospitable planet-sized semiconductor-based brain, with proportional intellect, multitasking ability and energy supply. Both the Creapii and the planet are classified in-universe in terms of humans, as are phnobes and drosks. Dom briefly mentions other races like the Spooners and Jovians, who are so far removed from humanity that there can be barely any meaningful discourse with them. Near the end of the book, Ig hints that there are stranger things still in the depths of interspace:
  "How blithely you use the word alien; you have no idea how alien a thing can be."
• Daystar and Shadow has the Hemn, a Hive Mind that resemble sea anemones, live in pools of a mysterious solution to avoid being killed by Earth's atmosphere, communicate telepathically via a mixture of ideas and images that coalesce into words, and refer to themselves as "I/we."
• Discworld:
  • While the Trolls 'look' like Humanoid Aliens their physiology is geological rather than biological. The troll brain is silicon, so they get stupider in warmer climates and more intelligent in colder ones, and they view the past as being "in front" of them because you can see it, so people travel backwards through time.
  • There's a bit in Lords and Ladies about how strangely elves perceive the world, apparently via a sensitivity to magnetism. They look human, but when their glamour fades they're smaller and greyer and more shriveled-looking.
  • Some books have Things from the Dungeon Dimensions, which apparently look like "a cross between an octopus and a bicycle". They're used for Lovecraft Lite storylines, especially in earlier books.
  • While the goblins in Snuff are humanoid and mostly comprehensible, their special talent for crafting unggue pots doesn't translate at all. Asked how he makes them, a goblin craftsman can come up with no human-speech explanation better than "I make pot!", stated and re-stated with different inflections.
• Doctor Who Expanded Universe:
  • The weirdest may well be The Shift from the Eighth Doctor novel Alien Bodies, which is a sentient concept who communicates by inducing minor hallucinations (the pattern of bricks in a wall suddenly looks like words, for example).
  • Other examples from the novels include sentient crystal creatures who shatter their limbs and grow new ones to suit their current surroundings, multiple living planets, a sentient virus that makes humans immortal, and non-humanoid squid aliens who carve obscene graffiti across the surface of the moon after they invade Earth. Also, a tentacle-monster body shape is stated to be the most common in the known universe (including more common than humanoid). And, of course, there are the TARDISes — some of their starfishness is described in the Live-Action TV section, but in some of the books they're not even physical entities at all: they're made of maths so complex it warps spacetime into something that only looks like matter.
  • Sky Pirates! says that the universe once contained really alien aliens — so bizarre that just being in the same room as one would drive you mad — but the Time Lords wiped them out long ago to prevent unpleasantness for anyone who might have run into them. (Except, inevitably, for a lone survivor who is the ultimate antagonist of the novel.)
• The Jenoine from Dragaera fall somewhere between this trope and Eldritch Abomination: while they're roughly humanoid, have some of the same emotions as us, and make use of similar tools and magics to those of Dragaerans or Easterners, they originate from another plane of reality where conditions are very different. For example, the Jenoine concept of "place" relates only to their mathematics, not to how they perceive the physical structure of the universe.
• Polish sci-fi writer Jacek Dukaj has a couple examples. The adynatosee in "Different Chants" (an Alternate History with Aristotlean physics and metaphysics) come from outside the sphere of constant stars. In the book every object and being has a morph (form) which influences the morph of other objects/beings near it. Their form is so alien that people start melting miles away from a city they built in Africa. Lute (the ice angels) in "Ice" look like a combination of a jellyfish with an ice sculpture they move by melting old parts and freezing new ones. The question whether they are even alive is never answered (though most people think of them as such) but leads the main character to the conclusion that he doesn't exist. Also they seem to have an aura of boolean logic - no uncertainties, quantum mechanics, wave-particle duality or even believable lies around them.
• Then there are the sandworms of Frank Herbert's Dune series, which are gigantic (as in up-to-half-kilometer-long) wormlike creatures that live in the desert. They begin life in several larval forms; starting out as a microbial "sand plankton", called "Little Makers", that serve as food for the adult worms. These eventually grow into a small, roughly diamond-shaped form called Sandtrout. The Sandtrout are later revealed to seal away all water on the planet, making them highly toxic to the hydrophobic adult form, and secrete the precursors to the addictive and Psychic Powers-granting spice, Melange.

E

• Greg Egan:
  • Diaspora features several very strange Starfish Aliens. In particular, the first aliens encountered by the descendants of the human race - floating algae mats whose method of reproduction produces, as a side effect, what amounts to a huge biological computer (based on a real type of formal system), simulating a 16-dimensional universe inhabited by sentient squid-things. In Orlando's story, he has to have himself cloned and modified multiple times, each version of himself translating for the next, to communicate between the post-humans and the first sentient aliens they encounter.
  • Schild's Ladder features another Universe that contains life. Said life, ranging from non-sentient fauna to sentient beings with their own civilization and technology, exists at the Planck scale. (To put that into perspective, that's about 10^-18 times smaller than the size of atoms.)
  • The people in Orthogonal live in a universe with different physics (you make energy by emitting, rather than absorbing, light), and their biology is similarly weird: they reproduce by fission, they extrude extra hands as needed, and the only thing they need an atmosphere for is to avoid overheating.
  • The Amalgam in Incandescence is a galaxy-spanning civilization where bodies and minds can be broadcast, replicated, and modified almost without limitation. Whatever Earth culture originally contributed to it is so far diluted that it's considered quite rude to ask someone whether they're "a child of DNA". Then there are the Aloof, who are so far removed from that that they sequester themselves in the Galactic Core and refuse all contact.
• Eisenhorn: The first book of the series, Xenos, features the Saruthi — starfish-like creatures utterly devoid of any kind of symmetry. Their main sense appears to be smell, and they have an incredible mastery of space and time - enough to perform interstellar teleportation. They can communicate with humans, when they want to, by steepling their fingers into a rather good imitation of human face, then speaking through it. It's unclear how much of their weirdness was always present, and how much is the result of Chaos corruption.
• Emperor Mollusk versus The Sinister Brain: The Sol Collective are a race of sentient helium gas that are native to the Earth's Sun. They lack any understanding of the concept of sound and communicate by flashing various colors. They nearly went to war with Jupiter when its ambassador wore a uniform with an assortment of colors that told them "Your mothercloud has a high melting point."
• Ender's Game: The later books (once you get past the Child Soldiers part) are pretty much all about the intricate moral distinctions between incomprehensible starfish aliens and Human Aliens — so much so that the series uses its own terms for the two: varelse and ramen respectively. The first species humanity encounters, the "Buggers", seem like clear-cut Hive Mind evil varlese — until it turns out that they only genocided half of humanity because they didn't realize mankind was sentient. In Speaker for the Dead the "piggies" have such an alien biology, it starts an interplanetary incident before the xenozoologist protagonists figure out what's going on. In Xenocide it is revealed that the piggies, after dying, become father-trees, and in order to do that, they absolutely require the "descolada" virus, which is lethal to humans (although the "recolada", the crippled version, works just as fine). At the conclusion of Children of the Mind it seems the protagonists may really have found some varlese-class starfish aliens; the ones who made the "descolada" virus, and communicate exclusively through chemical signals.
• The "gods" in Ken MacLeod's Engines Of Light trilogy are groups of extremophile microorganisms living in the Oort Clouds of just about every solar system. They have one commandment: leave us alone. The problem is, their "do not disturb" doesn't just mean physical proximity: they really don't like radio broadcasts, and they don't believe in gentle warnings. Enforcement is by asteroid impact; the extinction of the dinosaurs wasn't an accident.
• Everworld. While a fantasy series, two "alien" species are mentioned: the Coo-Hatch and the Hetwans. The Coo-Hatch are a weird race specializing in metallurgy; the large adults are often followed by strange little bugs which the characters guess may be their larval forms. The Hetwans are like giant flies whose males rip their partners apart during sex, the babies somehow being born during the process. (Also, they worship an Eldritch Abomination who wants to eat all other gods.)
• Wayne Barlowe's illustrated novel Expedition. Barlowe is vocally sick of Human Aliens and Rubber-Forehead Aliens and set out to create the most genuinely alien creatures he could think of, describing the ecology of the world in detail. Very few of them have the number of legs one would expect, only one named creature has eyes (and it is a single, atrophying eye at that; the creature seems to prefer keeping it retracted into a special chamber anyway), and only one named creature has anything resembling a conventional head with a "mouth" and "jaws" - and it turns out that the lower jaw can separate from the upper one and that it functions more like a mosquito's proboscis. And yet, he still keeps them familiar enough in subtle ways. There is also an alien of humanlike intelligence — and it looks more like what would happen if an octopus hitched a ride on a hot air balloon. Barlowe also painted portraits of many fictional alien races in his Guide to Extraterrestrials and Guide to Fantasy, focusing on very alien aliens including the Elder Things and Velantians mentioned on this page.
  • Alex Ries, a fan of Barlowe follows this with similar alien designs, one set based on nematode physiology with multiple limbs, you can check out his work at his online portfolio.
  • Nemo Ramjet is another Barlowe fan and has created the very alien ecosystem of Snaiad. Most Snaiadi 'vertebrates', have 2 'heads'. The upper head, the one that looks more like a head, to Earth-based perceptions? It's their genitals. The lower head, which looks like a set of genitals is actually their "mouth".
  • Korean illustrator Dong Hwa Moon (dilblo) does lots of these in 3D using ZBrush, see more at his blog.

F

• The denizens of Flatland aren't that difficult to relate with in psychological terms. However, they are physically extremely different. For starters, they are two dimensional objects, consisting entirely of various polygonal shapes. Flatlander men and women are segregated in society due to the fact that female Flatlanders have very sharp edges, and accidentally running into one can result in getting disemboweled. A big chunk of the story results when the narrator ends up encountering their own equivalent of a Starfish Alien; a three-dimensional sphere, which exhibits the ability to move in and out of the two dimensional realm at will and can do such things as poke the insides of our square protagonist. Then there are the Linelanders, one-dimensional beings that travel along a single line, and the King of Pointland, who in addition to being the king and sole inhabitant of his homeland, actually is his homeland.
• Joe Haldeman's novel The Forever War: The Taurans' minds are far more alien than their vaguely-humanoid bodies.
• Robert L. Forward had a few:
  • Dragon's Egg: The Cheela are small sentient slugs with twelve eyes on stalks, living on the surface of a neutron star. Their bodies are made of degenerate matter, so despite having about the same mass and physical complexity as a human, they are only about as large as a sesame seed. Because nuclear reactions happen much more quickly than chemical, time passes for them much, much faster than for humans. For all of that, their history and psychology have many similarities to humanity's.
  • Rocheworld: The aliens are very nonhuman—the Flouwen are aquatic blobs who love math and surfing and can compress themselves into rocks to think more effectively, the Gummies are elephant-sized five-limbed creatures who put down roots during the dry season and shed an arm during mating, and the "green giants" from the less than spectacular "Marooned on Eden" are mobile trees with detachable birds for eyes and racoon-like "gatherers" for hands. There are also sentient colored fungal mats with eyestalks, which puzzle humans with their seeming lack of reproduction (their population grows because the aliens often find feral individuals out in the tundra and bring them back to society), until they finally piece together how it works. A common species of shark swims about the ocean and moves towards volcanic vents near the end of their life cycle. Their corpses are blasted onto the tundra (the world is covered in ice, with oceans underneath) and then their ovaries develop into sentient fungal mat creatures. The sharks are born when the fungal mat creatures find a shark corpse on the tundra, eat its ovaries (a rare delicacy), and a few days later they get violently ill and dump their fertilized sewage into the ocean.

G

• Eric Nylund's A Game of Universe features some weird aliens, like an alien who is a colony of several insect species living in symbiosis, or beings who live in molten rock and protect their mineral resources by magically exploding any mining ship to approach their planet.
• Daniel Garro's short stories El niño mariposa and Mi corazón de metal introduce the metal-eating insectoid Ferrotophagous.
• The Nar of Donald Moffitt's Genesis Quest resembled two starfish on top of each other, had five-sided symmetry, communicated by feeling each others' cilia (although they had a verbal "small language" for less-complex distance conversations), and lived a thousand years before changing sexes and reproducing underwater. Their difficulties in understanding human psychology is what leads to the violent climax of the story. Moffitt's The Jupiter Theft featured the trilateral/radial, brutally utilitarian, and effectively all-female Cygnans. And an unnamed race that looked humanoid (and cute, and harmless) ... but, while more sympathetic than the Cygnans, was nonetheless dangerous. Aside from being predatory and having needle-sharp teeth, they could kill by causing acute allergic reactions.

H

• Haruhi Suzumiya:
  • The Data Overmind is some kind of non-corporeal, out-of-phase "data-lifeform." ^note  It's a concept based on an old theory that states that in its most basic form, the entire Universe is merely quantifiable information that can be manipulated; the Overmind is supposed to be a gestalt consciousness born of that information. What exactly it/they is/are, or how it/they think/thinks is never really explained, instead we get a lot of Techno Babble. Important to know is that its/their mind vastly differs from that of humans and that it/they does/do not communicate through language and therefore created the Interfaces (Yuki, Asakura, Kimidori) as its/their mediums. It appears that the entity/entities has/have different "voices" in itself with different opinions. Oh, and they can hack reality. Playing up on their godlike nature, in one short story Kyon is contacted by an old school acquaintance who had fallen in love with Yuki at first sight and now worships the ground she stands on. It turns out that he had the minor power to see her connection to the IDE which consequently overloaded his brain, as no mere mortal could possibly comprehend its true form.
  • Later, another entity similar to the Data Overmind is introduced, the Sky Canopy Domain/Macrospatial Quantum Cosmic Existence. While having a similar non-corporeal, reality warping nature as the Data Overmind, its mindsets and motivations are so different they are alien even to the Overmind itself. They are so alien to each other that despite knowing of each other for millennia they are totally unable to communicate, and the little contact the two entities have had is through a coincidental meeting of Yuki and Kuyou Suou on Earth, the latter being the Domain's human interface, and one much worse at fitting in than any of the Overmind's.
• Robert A. Heinlein:
  • Stranger in a Strange Land is a little vague about the nature of Martians, but they seem to be giant, globe-like fur-covered creatures who have go through a multiple-stage full body metamorphosis several times in life before eventually becoming just disembodied psychic entities. Their mode of thought is so different from that of humans that the Martian-raised protagonist's struggle to understand even the rudiments of human mentality are the nucleus of the book's entire conflict. A Martian's life has four stages: egg, nymph, adult, and Old One. All adults are male, all nymphs female: like some Earth fishes and amphibians, all Martians go through both sexes. Competition and rivalry happen solely among nymphs; the adult stage are so pacifist that even an awkward social situation might cause them to discorporate, shedding their bodies and becoming disembodied Old Ones. Oh, and all adults and Old Ones are incredibly powerful telepaths and telekinetics. And cannibals.
  • The Martians in Red Planet are similar in nature and lifecycle. The description of those in The Rolling Stones (1952) is less detailed since they are incidental to the plot so it is hard to determine their similarity.
  • Between Planets: Venusian "dragons". Giant, intelligent, six legged dinosaur like creatures with manipulation tentacles from their necks. The Martians are more humanoid with the description fitting that of The Greys.
  • Citizen of the Galaxy: While a member of Sisu, Thorby encounters two alien races. The descriptions of the races make it clear they're not remotely humanoid. Their cultures and philosophies are also very alien, to the point that Sisu doesn't even interact directly with one race.
  • Double Star: These Martians are different from the ones in Stranger in a Strange Land. Among other things, they reproduce through binary fission like human sized bacteria.
  • The Puppet Masters: The titular puppet master parasites are amorphous blobs that normally ride on a human on their upper back with some sort of neurological jack into the spine at the back of the neck just below the skull. And the human enjoys it too much to resist.
  • Starship Troopers: The Pseudo Arachnids or "Bugs". The Skinnies are more human-like, being much taller but proportionately thinner than humans hence the nickname.
• The Hitchhiker's Guide to the Galaxy has the Hooloovoo, a "superintelligent shade of the color blue", working on the Heart of Gold.
• The Host (2008) contains the "Souls", a Puppeteer Parasite species that essentially look like gracefully flowing centipedes with brain-controlling tentacles and silver blood, and then there's the way they reproduce, which involves the queen committing suicide by splitting into thousands of baby Souls. The main Soul character, Wanderer, mentions how no species they have taken over has been exactly the same. Other species mentioned include what can be described as giant intelligent dragonflies, gelatinous floating creatures, intelligent flowers, and seaweed with eyes and a psychic connection to the entire species.
• House of Shards has Lord Qlp, a Drawmiikh, whose species resembles a giant, brightly colored sea slug, with five tentacle eyes, which leaves a trail of slime as it moves. The Drawmiikh are completely unable to speak Human or Khosali languages. Like humans, they were conquered long ago by the Khosali, but nobody is sure they've ever realized that they'd been conquered. The concept simply doesn't translate very well. They normally have little interest in leaving their home planet. Which is fortunate for several reasons, not least being their horrible stench.
• Alan Dean Foster's Humanx Commonwealth: In The Founding of the Commonwealth, humans almost allied with both the AAnn (who are Lizard Folk) and the Pitar (preternaturally beautiful Human Aliens) instead of the insectoid Thranx... simply because the Thranx looked like bugs (rather cute bugs, but still). It turned out that the AAnn are militant bastards, and the Pitar wanted to take everything useful from everything else, then kill them to make room for themselves. Once they got over their mutual instinctive dislike of each other's physical forms, humans and thranx found that they got along pretty well.

I

• Janusz Zajdel's short story Iluzyt (about a science-fiction writer who finds a drug which gives you a string of story ideas) includes a description of "solipses", plant-creatures which are sapient, but have completely unreliable senses (they never see the same thing the same way twice); which is why none of them is even aware of the existence of anything beyond its own mind, regarding all their sensory input as hallucinations. Their consciousness also stretches for a couple of feet beyond their bodies, which means that anyone who gets nearby enters a sort of a mind-meld. It gets wonderfully trippy.
• Two examples come up in Imperial Radch. The Rrrrrr are described as snake long, furred, and multi-limbed, and speak in growls and barks. While certainly alien, they at least seem to be relatable. The Presger aren't described physically, but they are implied to be even weirder and are explicitly stated to use a completely alien logic — conversations with the Presger's "translators" reveal they are unable to comprehend individuality or identity in a way humans do: The translator in question, for example, is incapable of understanding that a person is the same person even if they lose a limb, instead treating the two as distinct entities, and ties its own identity (and partially its personality) to what other people call it.
• The Quarn In Fury Born (an expansion of Path of the Fury) are almost literally Starfish Aliens, being described as "a radially symmetrical cross between a hairy, two-meter-wide starfish and a crazed Impressionist's version of a spider". No matter their physical appearance, they get along with humans quite well. This is mostly due to the facts that both species 1) find the other's planets all but uninhabitable (helping prevent territorial warfare), and 2) share a love of biological/reproductive humour.
• The Inheritance Cycle features an Always Chaotic Evil species unrelated to any other creature, known as Ra'zac as larvae and Lethrblaka as adults. Ra'zac have a humanoid enough body plan, enabling them to go undercover among humans while wearing concealing cloaks, but their bodies are covered in insectoid exoskeletons instead of skin, and their faces have Black Eyes of Evil and sharp beaks. Meanwhile, Lethrblaka resemble massive pterosaurs with the same strange eyes as their young.
• Interstellar Pig by William Sleator features several of these, including a gas-filled airborne octopus and a mobile colony of carnivorous sentient lichen.
• David Alexander Smith's In The Cube virtually lives on this trope, with such beings as Koltsoi (huge hideously-ugly beings that "see" heat and move with incredible grace via hydraulic extension of limbs), Targives (never-seen genetic engineers who'll graft new abilities onto people, but always take something unexpected away in exchange), and "popcorn aliens" (oddball traders whose freaky grammar makes them all but incomprehensible). Even the Pfneri, small beaver-like beings who seem superficially familiar, speak a Starfish Language with no verbs, have senses so keen that they can Sherlock Scan and mime events that happened centuries ago, share a Hive Mind collective memory of their ancestors' experiences, and regard death as merely the completion of a story, hence something to find contentment in rather than grief.

J

• Jupiter, by Ben Bova: The Leviathans living on Jupiter are giant (as in kilometers-wide) conglomerations of independent parts, living in an ocean of liquid water suspended several thousand kilometers deep in Jupiter's atmosphere, feeding on organic molecules formed higher up in the atmosphere. They reproduce by going off on their own, away from the pack and "disassociating" — splitting into their individual cells, which then split themselves and reform into two new conglomerations, each with identical memories to the original. And they're intelligent.

L

• Last and First Men:
  • The Martians are sapient, airborne clouds of sub-microscopic organisms held in contact by electromagnetic radiation. Their bodies are subdivided into units specialized for different tasks (such as gathering energy, or seeing by turning clusters of their components into lenses to focus light into globules of water held in midair) and their entire species works as a single interconnected organism based on the same principles. They spend a long time assuming that the radio transmitters of the Second Men are in fact Earth's dominant lifeform.
  • The Venerians are a race of trilaterally symmetrical swordfish-like creatures that move by corkscrewing through the water and do not actually feed. Rather, they are powered by radioactive decay of heavy atoms within their tissues; they obtain years' worth of these in infancy and, when their stock runs out, are buried in mines of radioactive elements to rejuvenate. They are also marked by numerous alien behaviors, including feverish production of items which are them discarded or destroyed and a ritual where three individuals tear one another to pieces for no observable reason, whose purposes the Fifth Men are never able to discover.
• A.A. Attanasio's The Last Legends Of Earth is about then-extinct humanity being recreated as a weapon in a war between two of these species. Our recreator, Gai the Rimstalker, is more sympathetic; while her appearance gets little description but doesn't sound all that human ("lashing cilia" are mentioned at least once), and her origins in Another Dimension mean she could almost qualify as an Eldritch Abomination, she's capable of compassion and is fairly similar to a human in mindset, to the point of naming the solar systems she created after her dead parents. The ones who killed her parents, the Always Chaotic Evil zotl, are bat-spider creatures that feast on pain.
• The Leaves Of October by Don Sakers mostly revolves around a race of sentient, telepathic trees that can influence the evolution of other life forms by blowing themselves up. They can also communicate by altering the coloration of their leaves, which humankind does eventually learn to translate.
• Legacy of the Aldenata has the Posleen, described as hermaphrodite crocodilian centaurs, the Tchi... erm, crabs, which bear a very superficial resemblance to the earth arthropods they're nicknamed after (because the real name isn't really pronounceable with a human mouth), as well as the Himmit, which are basically double-ended frogs with a natural Invisibility Cloak.
• Various alien species in E. E. "Doc" Smith's Lensman series, including but not limited to the Palainians, who lived on Pluto-like planets and had metabolic mechanisms which extended into the fourth dimension in order to work, the Rigellians, who looked like large barrels on legs with 4 multiply-subdivided tentacles equally spaced around them, and the Eastern dragon-like (to an extent - they have an undetermined number of eyes (but more than eight), each of which is on a stalk, among other oddness) Velantians. Somewhat unusually for the period, and indeed for sci-fi in general, all three of these utterly inhuman species are humanity's firm allies.
  • The Meich in the Affectionate Parody Backstage Lensman.
    A group of entities indescribable by, or to, man stood, sat, or slumped around a circular conference table. Though they had no spines, they were something like porcupines; though they had no tentacles, they reminded one of octopuses; though they had no wings or beaks, they seemed similar to vultures; and though they had neither scales nor fins, there was definitely something fishy about them.
• The Oankali in Octavia Butler's Xenogenesis/Lilith's Brood trilogy...some of whom have been genetically altered to be more-or-less humanoid in outline. In their original state, they more closely resemble giant sea cucumbers.
• The first The Lost Fleet spin-off series introduces several truly alien extraterrestrial races. The Enigmas are snake-like and pathologically fear anyone knowing them, to the point of committing suicide to avoid capture and interrogation. The Bear-cows (AKA Kicks) look like large cuddly teddy bears, but their aggressive herd mentality causes them to instantly view any other species as either a predator (which needs to be killed) or a rival for the same resources (who also must be killed). Geary makes the mistake of smiling at them, causing them to recognize humans as predators by our canines. Like the Enigmas, they also commit suicide rather than be captured, but this is because they don't want to be eaten alive. The Spider-wolves (AKA Dancers) look like an unholy cross between those two animals, but are actually the nicest of the three. They share the concept of beauty with humans, especially when it applies to patterns, and are the only ones willing to communicate. Oh, and they think duct tape is the greatest thing in the universe.
• Stanisław Lem did like this trope, since it underlines the general theme of inability to communicate between sentients:
  • Fiasco has an interstellar expedition which spares no expense, even causing the break up of a moon of Saturn, goes to another star system to contact a race at a similar technological level than them, but they're so alien that communication is extremely difficult. By the end of the book you have a better idea of what the aliens might look like (living mounds, maybe colonies of insect-like beings), but it's still not entirely certain whether these things are really them.
  • In Solaris the ocean is-or-isn't sentient. In any case, it plays merry havoc with the characters' minds, but there's nothing to indicate any malice on its part.
  • In Eden the protagonists straight-up meet some aliens who are plain weird, not to the point that they can't be talked with (indeed, compared to the ones in Fiasco they're positively human), but still weird and not interested in a First Contact.

M

• One of the early influential examples is Tweel from "A Martian Odyssey", a bird-like alien whose language seems to use a different word each time for the same object, and who engages into bizarre ecstatic acrobatics when the human protagonist tells him he's from Earth. Even more so with the barrel-like creatures encountered later on, who spend all their time carting stones and sands just to bring them to a giant grinder, sometimes throw themselves into the grinder, seem to have a Hive Mind, and repeat mindlessly everything the protagonist says to them. While the protagonist comes to believe that humans might eventually be able to learn to communicate effectively with Tweel's species, the same can't be said for the barrel-creatures.
• Naomi Mitchison's 1962 Memoirs Of A Spacewoman features a few alien creatures with alien biologies completely unlike anything human. Of particular interest are the literal Starfish Aliens, the Radiate, who have five flexible limbs surrounding a central core and a complex language with a logic based on five values rather than binaries.

N

• Larry Niven:
  • The Known Space series includes the Outsiders, who are unaging, near-incomprehensible, Helium-3 creatures that can only survive in deep space at near zero kelvin; the starfish-like Jotoki who start life as a group of five wormlike swimmers and merge head-first to grow a single brain while maturing; the Grogs, cone-shaped beings who are immobile and use telepathy to lure small animals into their mouths; Pierson's Puppeteers, a race of innately cowardly herd animals with three hoofed legs, a brain in their backs, and two snaky heads who use their mouths and tongues as "hands"; and the Jinxian Bandersnatch, a limbless sentient slug the size of a freight train.
  • Many of the aliens in the Draco Tavern short stories.
  • The asymmetrical Moties from The Mote in God's Eye (which he co-wrote with Jerry Pournelle).
• In the Noon Universe cycle, the distinction seems to be between humanoid and non-humanoid, with the humanoid "group" actually forming two sub-groups:
  • The various outright Human Aliens present in the galaxy, who are all at much lower stages of development than humanity, such as the natives of Saraksh (Prisoners of Power), Giganda (The Kid from Hell) or the Dung Ages planet where Arkanar is located (Hard to Be a God), who are being covertly influenced by (Terran) human agents called Progressors to uplift them culturally. Those "aliens" are, in physiology/genetics, behavior and everything else, essentially identical to humans.
  • Then, there are other aliens, technologically comparable to Terrans, who are biologically radically different, but apparently still look vaguely humanoid in terms of body plan and have a psychology similar to humans, so they are counted as part of the "humanoid" group. Two of those have been described vaguely: Tagorians, who seem to have insect-like reproduction, with one life stage involving larvae, but otherwise seem not to behave like Bee People, and the plant-like Leonidans, who are a pacifistic philosopher society with Organic Technology. Both of those are on good terms with Terrans and meaningful communication and cooperation is possible.
  • On the other end of the spectrum, you have the non-humanoid races, into which the weird stuff goes. These include Intelligent Gerbil species like Golovans (who look like large Earth dogs with very big heads, have Psychic Powers and, while they do communicate with humans, a psychology which is hard to understand, with the few people who work as Golovan liaisons ending up quite frustrated) or the so-called Ark Megaforms from Space Mowgli, who seem to be either huge colonies of microbes or something like land corals, manifesting as large, immobile tentacle-like appendages. They do not directly communicate with the human expedition to Ark at all, but are somehow psychically linked to a human child (sole survivor of a previous expedition to the planet, having been born to two of the expedition's members), the titular Space Mowgli, and use him as a mouthpiece (and even that with somewhat limited results).
  • Finally, there are the Wanderers, a Higher-Tech Species who either vanished, ascended to a higher plane of existence or are simply extremely good at not being seen. The only evidence of Wanderer activity are occasional artifacts (including one anti-ship Kill Sat orbiting a planet) that are entirely incomprehensible to any other species technologically, are mainly made out of an entirely unknown substance, and yet still work quite well, as a human ship tragically finds out in relation to said kill sat). Most humans don't believe that Wanderers actually ever existed, while those in positions of power who do (due to witnessing examples of their technology, for instance) have more than a few sleepless nights due to the possibility that they might still be around. A few select characters like Rudolf Sikorski (head of COMCON-2, which is the closest the Noon Universe comes to a State Sec agency and counterintelligence program, for humanity as a whole, making Sikorski one of the most powerful humans in the setting) are extremely worried by the suspicion that Wanderers may not only still be around, but might also be covertly influencing / "progressing" humanity just as humanity itself does with the "lower" species. Nothing is known about the actual species besides the fact that they likely were/are radically non-humanoid.
  • On a meta level, the dichotomy between humanoid and non-humanoid races, with the somewhat unrealistic (for a duo of writers who started out writing hard SF and one of whom was an astronomer and computer scientist by education and trade, at least) amount of Human Aliens is justified or at least handwaved with the idea that beings evolving on planets with similar circumstances will be phenotypically similar due to convergent evolution, and will likely also be behaviorially similar (thus the "humanoid" status of Tagorians and Leonidans). This is not really stated outright, but it's a strong subtext between the lines in Beetle in the Anthill (the Noon Universe novel most intensely dealing with the Wanderers, not that that is saying much, likely by design). The extent of convergent evolution is somewhat hard to believe for the cases where the "aliens" are de facto humans, but Transplanted Humans was not a common trope when the books were written.
• In C. L. Moore's Northwest Smith story "Shambleau" the titular creatures show themselves as creatures resembling a smallish human-like cat alien, but when feeding reveal a true form that's apparently just a mass of tentacles. They're described as inspiring, among other things, the Medusa myth of a horrible creature that turns people to stone when seen.

O

• There are so many of these in the Old Man's War series that new recruits for the Colonial Defense Forces have to be specifically warned that non-humanoid doesn't mean evil. Revisited and played with in the later books of the series.

P

• Karl Schroeder's Permanence has aliens so weird, they can't talk to humans or other species without an artificial intelligence. This applies to writing as well, and the translations are never anything close to perfect. In the backstory, one intelligent species inhabited an entire planet, forming all living things there. The animals, plants, fungi, bacteria, etc were all one species, and had identical DNA. The scientists thought this was odd, until they found some human babies with the same DNA! (The babies basically had a human mind and an alien mind, which didn't communicate with each other.) When they managed to communicate to the aliens that they were sentient, the aliens responded violently, as they felt no species had the right to alter their environment. The humans had to quickly evacuate and nuke the planet. Other nearby planets were also inhabited by the aliens, and the human colonists there had to leave really slowly before the aliens could catch on to what was happening. Creepy.
• The dragonlike reptilian aliens - just known as "dragons" - in The Pit Dragon Chronicles are not particularly weird to look at, but they're telepathic and communicate in incomprehensible patterns of color, and it's very hard to tell how intelligent they are. So what do the descendants of penal colonies dumped on that world do? Capture them, pen them, and force them to breed and take place in bloody ritual fights, of course! Though this is said to have saved the dragons, as apparently they were dying out, surviving ones being too viciously territorial to know when to stop, and they were carefully bred to be less aggressive. It's still very hard to tell how their minds work and how intelligent they are, even in A Sending Of Dragons, where the main characters can perceive their sendings as words. Then thirty years later came Dragon's Heart, which had Series Continuity Errors to the point where dragons are clearly clever but not mysterious or weirdly insightful at all, and distinctly limited.
• In Anne McCaffrey's Petaybee series, the planet Petaybee was 'awakened' through the terraforming methods used to make the planet habitable by humans and communicates with its inhabitants through hallucinations that are given through a network of special caves. The first several books hinge around the Company who terraformed the planet trying to recoup its investment and the inhabitants' efforts to convince them of the planet's sentience.
• Anne McCaffrey's Planet Pirates series mostly focuses on humans and their Heavyworlder cousins. However, the series features other beings such as:
  • the Ryxi, a hyperactive avian species with a massive superiority complex and a powerful investment in making sure they're the only sentient avian species in the galaxy
  • the Bronthin, a bright blue horselike herd species, incredible mathematicians, absolute pacifists, implied to be the ones who forced humans to be vegetarians only to satisfy Bronthin cultural mores against predators, before helping to found the Federation
  • the Seti, reptilian with a cultural obsession with gambling
  • the Lethi, fuzzballs only sentient in group of six or more, require a block of pure sulphur to feed on at all times
  • the Weft, shapeshifters who naturally resemble spiky horseshoe crabs, have five sexes and are permanently rendered sterile by space travel, and oddly enough the most human-compatible species in the setting
  • the Ssli, giant barnacles that can "taste" subspace and navigate FTL
  • and maybe the strangest of all, the Thek, roughly pyramidal-shaped blocks of stone with molten cores who feed on transuranic elements, grow larger as they age (up to the size of mountains), are quite possibly immortal (the remains of one who had been subducted by continental drift was found, and communicate very slowly with other races (a conversation with a large one can last a human lifetime). They are also Sufficiently Advanced Aliens who are powerful enough to dictate terms to the rest of the Federation (when a Thek Cathedral happens, you will listen, and you will do what you are told). It is strongly implied that the Thek are the source of rumors about the Others, an unknown species that consumes the surface of worlds utterly to feed their monstrous appetites.

R

• Robert Reed's aliens are starfishy more often than not:
  • The eponymous aliens of The Remarkables start life as dumpster-sized landbound sea urchins, before metamorphosing into sessile willow tree-like creatures with eyes large enough to detect ships in orbit. They are intelligent and form "forests" with human guardians, who wage war against other forests using early 20th century technology.
  • The native intelligent species of High Desert in Beyond The Veil Of Stars are a Hive Mind of sorts; they possess six rodent-like members, and one helpless brain in a thick, rounded skull. The rodents function as the limbs of the brain, and roll it across the ground when traveling.
  • The Coronas of The Memory of Sky, a Great Ship novel, are building-sized Living Gasbags that breath hydrogen, are effectively ageless and possess dozens of mouths on an extendable tongue. Their guts and bones are highly valued by the humans who live in the upper half of the Hollow World; when a Corona rises from its realm, dozens of human zeppelins descend upon it with harpoon guns to kill it then drag it to the rim of the world where they extract the blood (to filter out metals) and use the bones for construction material.
• Also by K. A. Applegate, the Remnants series features different alien species, of which the Squids are the most normal. The Blue Meanies/Children are described as looking like giant cats with tentacles they use for sign language, the Riders have two different-looking heads (one is basically just a mouth), and the Shipwrights look like starfish, but with transparent skin.
• All of the aliens in T. Jackson King's Retread Shop are starfishy. One of the main characters is a many-tentacled, many-eyed, telepathic plant alien. The villain is a Tet, a four-armed giant salamander. Other species include the Dorsellians (a species of flying manta ray-like beings), the Hecamin (which resemble lions with manipulatory tentacles for manes, and have some sort of insufficiently-explained Bizarre Sexual Dimorphism), the Bareen (numerous furry, spherical beings that combine to form "clumpings"), the Melanin (another species of Plant Aliens, this one photosynthetic and resembling a levitating shrub with one eye and an elephant-like trunk) and the Chellaquol.
• In Revelation Space Series, every alien is a Starfish Alien. The Pattern Jugglers are semi-sentient algae-like aliens that inhabit water worlds, and function like a living library. The Grubs are grublike aliens that hide between solar systems in tiny ships to avoid extinction by the Inhibitors. The Inhibitors are 'post-sentient' Transhuman Aliens which wipe out all space faring races in order to save the galaxy during the Andromeda galaxy collision in a few billion years. Humanity is exactly the kind of problem that the Inhibitors were designed to solve, ergo, all of the non-starfish (i.e. similar to human) species that do things like build cities, launch colony ships, etc now exist only as fossil records have been wiped, while the ones with radically different physiology, psychology or both often still exist since they don't fit the criteria. Thus, outside of us, it's pattern jugglers and shrouders all the way down.

S

• The Sector General novels have an entire alphabetized classification system to describe the tremendous variety of metabolisms, body types, and environments of alien species. And even then, they often run into lifeforms that defy classification.
• One story in The Ship Who... Sang, Dramatic Mission, is about an attempt by the primarily human Central Worlds Federation to trade with the technologically advanced inhabitants of Corviki, a world with a methane-ammonia atmosphere. Corviki resemble hydrozoans, having large sac-like bodies trailing complex tendrils, and live in what humans percieve as something similar to an undersea Carribean landscape surrounded by colorful seaweed. Despite not initially being able to leave their homeworld, they reached out to make contact with humans surveying them from orbit. The Corviki were quite intrigued by Shakespearean plays and worked out a deal where human actors in orbit would inhabit Corviki "envelopes" prepared for them and stage a production of "Romeo and Juliet", teaching it to native understudies if it proved popular. In exchange Central Worlds would get some technology it was very excited about. The Corviki prove to be rather more alien in thought than the actors might have expected. One identifying itself as their "Manager" says this to an actress who's not feeling it.
  "There is no logical reason to withhold energy. Conservation is not the aim of this experiment. We are assessing the effects of this form of energy expulsion on the pressure-senses and dominance factors. You inhibit this experiment. Therefore, lose energy as the equative factors require."
• The Tralfamadorians from Slaughterhouse-Five experience time in a non-linear fashion, and as a result have an entirely different concept of literature, which details many unrelated moments, and is ultimately incomprehensible to humans. They're also shaped like plumber's friends topped by hands, each with a single eye in the palm.
• Michael Swanwick's novella Slow Life describes an encounter of a human expedition with a hive intelligence underneath a methane lake that is bewildered to encounter a mind separate from its own: "Are you me? Why? Why aren't you me?"
• In Stanisław Lem's Solaris, the eponymous alien is not only a planet and a liquid, but also his thoughts are so different from humans', that the scientists investigating it are going crazy. Also, presumably, various phenomena occurring on the planet are its mind processes, leaving the question of how do the scientists not mentally injure the planet by doing research. It is also possible, that in fact the planet does investigate humans.
• The Crawler from The Southern Reach Trilogy by Jeff Vandermeer defies the biologist’s attempts to describe it, though she does her best. She says at one point that its form changed so rapidly that it seemed that it was mocking her inability to comprehend what she was looking at.
• The eldil from The Space Trilogy do not exist in space as humans do, so that they need to consciously match the speed of the Earth as it rotates on its axis and revolves around itself. They also manifest as completely different beings depending on how "far" they are from you, so they can look like the nightmare about the apocalypse one minute and then appear as a circle of eyeballs just by "moving" slightly. When you live in the space between the planets, weird stuff like that happens to you
• The Star Bridge series of young adult novels by Ann C Crispin has any number of these aliens. The dominant (though peaceful) aliens of the galaxy are giant snakes, which preside over a menagerie of alien forms. The strangest one is most likely the race of amorphous blobs that communicate only through vibrational pulses, although the blanket-sized telepathic fungus alien that remained a major recurring character for most of the series got more screen time.
• Most of the aliens in the Star Carrier series qualify. Of the ones revealed in the first two books, the Turusch evolved to live in Venus-like atmospheres and exist as pairs of cylindrical organisms with a Starfish Language wherein each body speaks a separate line and the harmonics between the two lines of dialogue create a third. The H'rulka are colony organisms (think Portuguese man o' war) that form a Living Gasbag averaging 200 meters long and evolved in the upper atmosphere of a gas giant. The most human-like psychologically are the Agletsch, a Proud Merchant Race of spider-like aliens that get drunk off vinegar and treat eating as an intensely private act (which is good, because their method is Nausea Fuel for humans). Later novels introduce and describe the Slan, a race whose primary sense is echolocation (think bats Up to Eleven), who are even able to use it as X-Ray Vision. Since their light-sensing organ is rudimentary at best, they don't even understand the concept of "space". To them, it's one big airless cave, through which they require spaceships to move to get to another habitable cave. The Grdoch are large rolling spheres with dozens of mouths, who really like to eat other beings. Unfortunately for humans, they happen to match the Grdoch protein requirements. They're also almost always pregnant and release their offspring at times of stress, frequently eating them or using them to distract larger predators. Then there are the jellyfish-like aliens who come from a Europa-like world. They have a reducing-medium metabolism (rather than oxidizing-medium, like almost all the other species), meaning they intake hydrogen and use it to reduce nutrients. Because of this, they live very slowly and perceive every other race as The Flash. They "see" with something called "electric-sense", which is also how they communicate.
• In Poul Anderson's Starfarers, one of the sentient species is an intelligent layer of star. Not the whole star, just part of its skin.
• The "Bugs" from the Starfire novels by David Weber, which also qualify as the Horde of Alien Locusts.
• Star Maker has literal Starfish Aliens: an intelligent species that evolved from starfish-like ancestors. It also features beings that resemble living ships, intelligent insect swarms, and most alien of all, intelligent stars and nebulae.
• The Corasians from The Star of the Guardians are borderline-Energy Beings that look like giant, glowing amoebas in their true forms, but typically inhabit robotic exoskeletons to move about more efficiently in. Psychologically they've got a Hive Mind and generally don't relate to non-Corasians as anything but food or a convenient source of new technology to steal, though they're smart enough to work with other species on a temporary basis if it gets them one or both of these things in the long run. Pretty much all the other species in the series consider them a menace, and attempts to find common ground with them typically fail miserably.
• Sergey Lukyanenko's The Stars Are Cold Toys duology features anything from Human Aliens (although those are revealed to be cousin races all originating from a common source) and Beast Men (e.g. the rat-like Alari and the mantis-like Hiksi) to truly alien creatures. For example, the Torpp are sentient plasma clouds encased in magnetic bubbles living in star coronas and able to move through space without ships (although it's not clear if they're capable of independent FTL travel). At least two races are worm-like in appearance. One specializes in mining for the Conclave given their natural affinity for burrowing. The other lives in underground lakes on a Mars-like world and has a mouth with large teeth at each end and doesn't appear to have anything resembling a head or even the concept of "front" and "back". There's a race of living computer lizards (they're revealed to be artificial constructs) and Hive Mind symbiotes able to meld with nearly any biological species and act as Translator Microbes.
  • Lukyanenko's Spectrum also features some strange races. One is a sentient race of 3-foot amoebae whose homeworld is covered by a layer of water with such a high surface tension that other races can walk on it. However, if they spend more than a day on that planet, they will die from their own body fluids adopting the local surface tension (i.e. blood can't flow anymore). Members of another race live only for six months and die shortly after giving birth (which implies that they can never have a positive population growth). Additionally, they give half their memories to their offspring. Another race looks like Lizard Folk, except only their males do. Their females are non-sentient, are much smaller, move on all fours, and are usually treated as pets.
• Star Trek Expanded Universe:
  • Diane Duane loves including this trope in her novels, adding such members of the Enterprise crew as giant snowflake-shaped silicon creatures, a bipedal catlike being who doesn't comprehend past tense, two-meter-long lizards, a Starfleet captain who is basically a giant slug, a glass spider with twelve legs who wrote the laws for a universe, and —yes— a Horta lieutenant (basically a sentient lump of rock that looks like a giant pizza). The Federation gets a lot more multi-cultural when she's writing. And that's just in Starfleet - she also introduces such species as sentient rocks who can manipulate time, creatures who are basically intelligent amoebae, and trees with a consciousness.
  • Greater Than The Sum has the Enterprise encounter an intelligent star cluster. That's right, a 15 light year across region of space containing dozens if not hundreds of star systems in which each planet functions like a neuron. It's so alien that even though it is aware of the Enterprise and can comprehend their desires the only way it can communicate with them is by giving telepathic metaphorical impressions to a meditating human-vulcan.
  • Star Trek: The Captain's Oath has the Agni (not their real name, but if they have one, they don't give it), who can only comfortably live on planets like Venus. They look like a mix between snails and octopuses, and due to the nature of their environment don't have eyesight like we do - they see in infra-red. This makes communication almost impossible, since how do you communicate with beings you can barely tell exist at all? They also don't have the general concept of ownership, thanks to the nature of their planets. In the end, the Federation and the Agni reach a mutual accord, but it's acknowledged that they're so different, aside from not attacking one another, there's not much they can offer the other.
• Star Wars Legends is full of Human Aliens, Rubber-Forehead Aliens and Furry Aliens, but a few are obviously non-humanoid.
  • The Celegian are giant brains with a few tentacles dangling from their Cerebellum, and the Wol Cabbashites are sentient, telepathic barnacles that can live in vacuum and communicate with their electromagnetic tongues.
  • The Sarlacc is further elaborated on. Scientists argued on it being an animal or a plant, eventually settling on crustacean. It colonizes alien planets with spores launched into outer space. The Tatooine one is a titanic sessile predator that manages to survive the sparse ecosystem of a desert environment by digesting prey unbelievably slowly. It keeps its swallowed prey on messy biological life-support while it digests them, so it can literally feed upon their psychic and physical torment and pick out the choicest neurological morsels to absorb into its consciousness, which it generates from the collective minds of its captive nourishment. It has a nightmare digestive system that rather neatly encapsulates the concept of hell as a living organism.
  • That giant space slug that ate the Millenium Falcon in The Empire Strikes Back? Xenobiologists believe the Exogorth was once the dominant life form in the galaxy and that the ones they see today are the last remnants of this once-great race. No one has any clue where they came from or what happened to cause them to fall. To quote Arkoh Adasca:
    "They're the last remnant of a species that predates history—an unlikely being, if ever there was one. No one knows how or why they evolved—just that we have found a number of them in the galaxy, going about their business... Time has no meaning for such a creature... We thought for a time that they might have once been plentiful in the galaxy—and the ones we find now are the only ones left."
  • One species that possibly represents the very threshold between this trope and Humanoid Aliens are the Krevaaki. They have shrimp-like bodies and crab-like pincers...and at least two of them were Force-sensitive Jedi Masters, and could wield lightsabers!
  • The Shard, a race of sentient, luminescent, immobile crystals that communicate exclusively via some kind of electromagnetic resonance. They grow in clusters and share a kind of group mind, spending their unmoving existence immersed in deep contemplation. However, it's possible for a single Shard to be cut free from its "siblings" and live as an independent organism with a droid body, after which they begin to rapidly develop individuality and more "human"-like personalities. During the Galactic Civil War, a surprisingly large number of droids working for the Rebel Alliance were secretly carriers for Shards.
  • The Morodin of Varonat (a planet near Bespin) are a tragic example: they are sentient, but look like multilegged sauropods and are therefore hunted by poachers.
  • Galaxy of Fear has a planet that somehow, thanks to mad science, is alive and eats people. Elsewhere there's another living planet, but D'vouran is much less human, for lack of a better word, than Zonoma Sekot. It never communicates in words, but seems to have a degree of intelligence: it takes prey slowly and carefully, hides evidence so they won't be spooked, and supports the symbiotic/parasitic Enzeen so that they'll do whatever they can to induce more people to visit and stay.
• The Sten series features occasional wildly nonhumanoid creatures, such as the peaceful race of floating jellyfish, or a ring of sentient polyp creatures that appear to be permanently installed in a ring inside a large Customer Service desk. There's also one literal example of a Starfish Alien, and it's nightmarish for three reasons: it's as tall as a man, it runs through waist-deep water as quickly as a man can on land, and it's got a thresher maw in its center. The creature, called a "gurion", is only encountered once in the series but remains one of the most memorable and horrific of all the alien entities Sten fights.
• The aliens in Stolen Skies exist in multiple dimensions, and have bodies and minds fundamentally different from anything on Earth. The few times a human has interacted with one with any degree of success, it's been when one of the aliens has become trapped within local spacetime and attempted to make some (always incomplete and ultimately unsuccessful) attempt to adapt to local conditions.
• Ted Chiang's short story "Story of Your Life" is about a human team's attempts to study and communicate with an alien species. Eventually, the linguists realize that the alien written language is nonlinear because the aliens don't have our idea of time. Learning the alien language enables the linguists to perceive the future, but not to change it.
• Strata references this - though the protagonist's Kung and Shand alien friends are civilized, and can speak English, they are still alien no matter how familiar they look. Played more straight with the Efht race, which both look and sound like stereotypical Starfish Aliens.
• In Gregory Benford's The Sunborn humanity discovers strange alien gas-bags on Pluto when some of them start feeding off of the heat given off by their probe. Said alien gas-bags have sapient intelligence. And then a bunch of robotic drones descends on Pluto apparently eating said aliens. These robotic drones turn out to be the equivalent of microscopic instruments used by what is apparently an intelligent race of electromagnetic waves.
• The single-celled, collectively intelligent, abyss-dwelling Yrr from the novel The Swarm. The novel goes out of its way to enforce this trope, in fact.

T

• The Tangled Strings Of The Marionettes by Adam-Troy Castro has the Vhlani, who resemble black spheres with eight whip-like tentacles. Humans have great difficulties understanding their language, which consists of "dancing". Some humans are trying to learn the language via extreme body modification, but as the title alludes, they only have limited success.
• Tales of Kaimere: While the notable megafauna are descendents of Earth animals harvested over millions of years, the true endemic lifeform of Kaimere are various single-cell organisms. The most notable is the portals, hives of single-cell organisms that can scan objects or lifeforms and recreate them elsewhere to improve their habitats. These organisms can also inhabit the bodies of earth-derived organisms and even grant them abilities like shapeshifting. In a sense, magic is the native lifeform of Kaimere. While none have achieved true multicellular forms, some form colonies with other species of Kaimerian single celled organisms to be strange aeroplanktonic organisms that float high in Kaimere's atmosphere, much like siphonophores in Earth's ocean
• "A !Tangled Web (1981)": The !tang. They look like a perambulating haystack with an elephant's trunk protruding; they have two arms that they keep hidden. They have multiple genders, and tell each other apart by sonar.
• Tais Teng's aliens tend to fall squarely within this category. Examples of note include various species of organic spaceship, the Wessyn Engineers (something like bus-sized beetles, but with technology that allows them to build on a stellar scale and slip into a two-dimensional state), a species thriving on planets where the surface temperature approaches zero K, and the giant Lespadin who are used by another alien species as walking cities. It is implied that the few species really worth meeting have already achieved Enlightenment, becoming superior beings that mere humans cannot communicate with. What remains of the universe is "just another ghetto".
• In S.A. Swann's Terran Confederacy universe, the Paralians are described as 'squid-dolphins'. The Helminth are meter-long worms which have technology and build cities, but human scientists are largely unable to communicate with them. The Race are colorless amoeboid blobs.
• Terry Bisson's short story, "They're Made Out of Meat" consists of a dialog between two beings trying to come to terms with an unthinkably bizarre and disturbing discovery: a planet with a race of sentient beings made out of meat! The other aliens see humans as something so strange and implausible that they decide to erase all records of our existence as intelligent life forms and records of contact.
• Peter Watts' "The Things" subverts this by taking the creature from The Thing (1982) as the point of view character. Humans are really creepy. For one thing, they don't shapeshift, like, you know, the rest of the Universe. And their minds are not distributed to every cell of the body, but rather curled up inside tumorous, cystic nerve fibers locked inside bony cavities. What a miserable existence they must have.
• The Hrangans, powerful psychics and masters of massive slave armies composed of beings of varying intelligence, of George R. R. Martin's Thousand Worlds Science Fiction stories. They were apparently so alien that communication between then and humans was basically impossible. Even human psychics weren't able to get anything from Hrangans but mental static. At any rate, the Hrangans didn't feel like talking, they were much more interested in conquest.
• The Baby Eaters and the Super Happy People from Three Worlds Collide by Eliezer Yudkowsky. The Baby Eaters are crystalline bugs who have far more children than they can afford and eat the excess ones. They are theoretically advanced enough to develop contraception, but have not because in their equivalent of the Stone Age eating your excess children was an important method of signaling loyalty to your tribe, since it showed you were willing to sacrifice your beloved children to make sure the tribe wouldn't run out of food. So the Baby Eaters believe eating babies is the basis of morality and their word for "to be moral" is the same as their word for "to eat babies". The Super Happy People are a race of writhing blobs that use DNA for thinking and communicating in addition to reproduction. Their word for "to have sex" is the same as their word for "to talk". They have genetically modified themselves to be free of all pain except some mild discomfort to warn them if something is damaging their bodies. They believe humans are insanely cruel for not doing this to their children.
• In Transpecial, the glen are carbon-based, like all other known lifeforms, but they evolved in such a high-gravity, high-pressure environment that they're made of diamond. Twice during their adult lives they undergo a complete metamorphosis in which their genders and personalities change.
• The Masters, the antagonists who drive The Tripods, are tall cone-shaped creatures with three eyes, three legs and three tentacles. Physically have a low tolerance for ethyl alcohol (which becomes a major plot point later), and an extremely sensitive area between their respiratory orifice and ingestive orifice, making the lightest brush extremely painful. They breathe a thick, greenish gas that is deadly to humans, bathe in near-boiling water several times a day to keep moist, drink gas bubbles as an intoxicant, and seem to have only one disease. Psychologically, they are incapable of lying and cannot grasp the concept of fiction or exaggeration (though at least one of them gains a firm understanding of sarcasm), are incredibly tolerant of hardship and difficulty (to the point of becoming ill if they don't work hard), seem to possess a strong strain of fatalism, and die if they're put in a situation they feel they can't escape from (as shown by the one Master captured alive by the human resistance, who keels over dead when he is abandoned on Earth by his departing fellows at the end of the trilogy.)

U

• In Uplift, few aliens are bipedal. There's one species that looks like a stack of wax doughnuts, another with five-point radial symmetry, and one species that has wheels. The other orders of life are much stranger, including quantum entities and intelligent memes.

V

• The short story "The Very Pulse Of The Machine" by Michael Swanwick has a lone human astronaut on Io who begins hearing voices in her radio. She may be hallucinating but it's strongly suggested that they're real, and if they are, Io itself is alive and talking to her via electric currents in its crystallised-sulphur surface.
• Vernor Vinge:
  • Zones of Thought:
    • A Fire Upon the Deep has the Tines, a race of seal-headed dog creatures that communicate through ultrasound that is so fast and complex that it might as well be telepathy. Each individual Tine is nonsapient, but when four or more combine, they become an intelligent individual. However, the ultrasound interferes if too many Tines get close together, so when the number of single Tines in a group exceeds eight, they start to get dumb again. As a result a civilization of "individual" packs of around 3-8 Tines has grown. Some individuals live for hundreds of years as they gradually replace members that die (and if both parents of the new member also belonged to its new collective, the collective's personality is supposed to stay exactly the same). A lot of plot points hang on their unique physiology. For example, one of the villains attempts to escape his enemies by literally splitting himself, murdering parts of some of his dupes and merging his constituent Tines into the remnants of their collectives, intending to recombine them back into himself, once out of the danger zone. He succeeds... partially.
  • There's the Skroderiders, sentient sea-lily creatures with no short-term memory that ride around on computerised wheelchair-like skrodes. There are also the Powers - beings who live in the Transcend, and have crossed The Singularity (a term of Vinge's coinage). By definition, they're like Starfish Aliens, minus the anthropomorphism. In the Beyond, school kids study them in Applied Theology.
  • In A Deepness in the Sky, he created the Spiders of the On/Off Star, giant arachnoid aliens that hibernate every few decades when their star goes into a cool period. They are more human psychologically than the Tines though, or, at least, they seem so, because the spider sections of A Deepness in the Sky are supposed to be texts written by human researchers, who used Translation Convention, while Tines interact with humans directly from the beginning.
  • One of Vinge's greatest alien races are the Shimans from the story "Original Sin". They are kangaroo-like in appearance and highly intelligent, but they only live for two years before they become asexually pregnant with voracious babies that eat their way out of their parents. They retain that incredible hunger all their life and have a terrible time building a civilization without eating their coworkers. The only way they succeed at all is that they are smarter and more energetic than humans. One of them remarks to a human that humans are lucky because they are naturally good, whereas Shimans have to work very hard to be good.
• The entities in Clifford D. Simak's The Visitors resemble nothing so much as enormous 2001 monoliths, jet black and with a surface texture like tree bark. They don't need spaceships and arrive on Earth famished—but they don't consume meat. They're xylophagous (they consume wood).

W

• In David Gerrold's The War Against the Chtorr novels, mysterious plants animals and viruses from another planet are choking out and dominating the Earth's own ecology. The only reason humans call them "Chtorrans" is because that's how we perceive the sound made by the most dangerous of the new ecology: The giant furry man-eating gastropedes. The protagonist experiences quite a bit of this mysterious new ecology firsthand, including a "storm" of fibrous spores that covers part of California in what looks like 15 feet of cotton candy.
• H. G. Wells' The War of the Worlds (1898) was the Trope Codifier, particularly for the common "cephalopod alien" variant. Wells designed his Martians by starting out with a humanoid, then eliminating all organs (limbs, digestive tract, etc.) that he felt advanced technology would render useless and/or inefficient.
  "A big greyish rounded bulk, the size, perhaps, of a bear, was rising slowly and painfully out of the cylinder. As it bulged up and caught the light, it glistened like wet leather. Two large dark-coloured eyes were regarding me steadfastly. The mass that framed them, the head of the thing, was rounded, and had, one might say, a face. There was a mouth under the eyes, the lipless brim of which quivered and panted, and dropped saliva. The whole creature heaved and pulsated convulsively. A lank tentacular appendage gripped the edge of the cylinder, another swayed in the air. Those who have never seen a living Martian can scarcely imagine the strange horror of its appearance. The peculiar V-shaped mouth with its pointed upper lip, the absence of brow ridges, the absence of a chin beneath the wedgelike lower lip, the incessant quivering of this mouth, the Gorgon groups of tentacles, the tumultuous breathing of the lungs in a strange atmosphere, the evident heaviness and painfulness of movement due to the greater gravitational energy of the earth—above all, the extraordinary intensity of the immense eyes—were at once vital, intense, inhuman, crippled and monstrous. There was something fungoid in the oily brown skin, something in the clumsy deliberation of the tedious movements unspeakably nasty. Even at this first encounter, this first glimpse, I was overcome with disgust and dread."
• Waste of Space: In one of Zan's conversations with Dashiell, she reveals his true form to him. It's that of a giant jellyfish covered in blue dots (likely eyes) and a dozen tube-like tentacles around her body.
• The alien species in Paul Harland's Water To Ice. Some are so strange and ancient that nobody has a clear idea of what they are at all. The Kysx, for instance, are flying balls of fuel and fire, said to have arrived in spaceships half a meter in diameter and two kilometers long. The Rrith have the body of a ray and communicate by shifting the pattern of the fur on their back. The Ftott are big sponges whose limbs are blades of bone; they "talk" by hacking specific parts off their opponents...
• "When the Yogurt Took Over" by John Scalzi features an intelligent dairy product that conquers the world. The concept originated in a critique of Atlas Shrugged in which Scalzi argued that Ayn Rand's "hero" John Galt is clearly the bad guy of the piece from the perspective of anyone else, and that in fact he acted so little like a sympathetic human being that the story would make more sense if he were a sentient cup of yogurt. Scalzi then couldn't get the idea of such a being out of his head and wrote the story.
• The illustrations in WondLa are just chock-full of them. The first one Eva meets is humanoid enough save for the backwards-bending legs, but it pretty much ends there, as she comes across, among others, an upscaled water bear, a multi-armed hovering fortune teller who doesn't speak with his mouth, and a giant praying mantis-like queen.
• Frederik Pohl's The World at the End of Time features plasma-based aliens who live inside stars and don't care much for "slowlife" like biological beings.
• A World of Difference features a planet where six-way radial symmetry is dominant. The native people have six eyes on stalks, a mouth on top of their bodies pointing upwards, six arms and six legs spaced around their bodies, and no defined front or back.
• To the Ixchel, in A Wrinkle in Time, light and vision are alien concepts, but being empathic is utterly commonplace. Biologically, they're huge, eyeless psychics with tentacles. They're also the kindest, most wonderful people you've ever met. They're willing to give an utterly alien family shelter and cure their semi-corrupted daughter with no thought of being repaid after said family basically admits that humans would probably have killed them if they had come to Earth instead. Maybe there's a reason their planet shares its name with the Mayan goddess of birth and medicine...
• Worm: The eponymous "worms" or "entities" revealed near the end of the story. They have long since abandoned their original, dead world and now travel throughout the multiverse seeking ways to grow. Two individuals are the source of all the superpowers in Worm, having come to Earth as the latest in a long line of worlds and civilizations they have parasitized and consumed. These beings exist in multiple parallel realities simultaneously and can move between them as casually as taking a step. They possess millions upon millions of superpowers and further retain the scientific knowledge of not only their own, ancient race, but of every intelligent civilization they've consumed. To say their thought processes and outlooks don't resemble those of a human in the slightest is an understatement. They're so complex that it's stated the tiny "shards" of themselves they shed (ie, the superpowers everyone has) are themselves living things with their own form of life and intelligence.

X

• Xanadu (Storyverse): Lalannas, the alien species designed by the main character in "Five Hours, Thirty-two Minutes", live in liquid ammonia at temperatures of -100 Celsius, breathe liquid hydrogen, and are born as non-sapient larvae that become people by merging with one another. Adults are composite beings with two minds, which share control of the body and alternate in taking control of sense organs and extremities.
• Les Xipéhuz, an 1888 short story by J.H. Rosny, seems to be the trope maker. While the eponymous creatures are never stated to come from outer space, they are non-organic lifeforms with cone- or cylinder shaped bodies with a Heart Light, talk by drawing symbols on each others bodies with lasers and reproduce by merging over night and creating a new individuum from smoke that's much bigger than the adults and shrinks as it gets denser.
• Xeelee Sequence: Every single alien is as alien as one can get from hard science-fiction. Not a single one of them look even remotely human. The most comprehensible aliens are the Squeem, which is hive-mind heavy race of aquatic squid-fishes, and the Spline, which is a mile wide space whale-cyborgs. The other races are truly incomprehensible in their genetic makeup. The Qax is a race of 90 meter wide sentient convection cells (AKA, living thunderstorms). The Silver Ghosts are a 1-ton hyper-reflective, post-scarcity, silver sphere that is a superorganism made up of creatures that actively violates planck's constant. The Quagmites are ancient micron-sized race of living quark-gluon-based plasma. The titular Xeelee are living defects of space-time living in symbiosis with bose-einstein condensate superfluid creatures. The Photino Birds are a race of non-linear, super-symmetric dark matter aliens. And the Monads are abstract god-like entities that live in the substrate quantum foam between universes and dream realities into existence.

Y

• Young Wizards: The first book includes "Fred", a sentient white hole. This begins a long succession of various bizarre species, including sentient pine trees and various insectoid species.

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