The Top Ten Alien Species in Science Fiction

Okay, first? Let me just say that I hate the term “alien race.” I know it is tremendously nitpicky, but “race” means in biology “subspecies with really unimportant differences,” or more often in modern cultural usage “social distinction with no biological importance whatsoever”, and so it is not really appropriate to use when you really mean “species.” You wouldn’t say that baboons are a race of gibbons or that elephants are a race of horses or that sea urchins are a race of, I don’t know, birds. That is all perfectly ridiculous. And aliens that evolved on a different planet are a lot less related to us than baboons or mice or even sea urchins. So, species, please, not “race.”

Okay, with that rant out of the way, what are some of the best alien species in SF?

In order to be among the “best”, an alien species has to be not-human psychologically and culturally as well as physically — and it has to be believable, or at least seem believable when you’re reading the story. It helps if it is compatible with what we know about animal behavior, which never arises in a vacuum — instinct as well as physiology arise in response to ecological pressures, after all. And, incidentally, when you hear the word “instinct,” you should think about emotions, because emotions are the experiential face of instinct. Think about it this way: The fear that makes you run away from a charging grizzly bear is how you experience the underlying flight instinct. The intense protective, possessive feeling you get when you look at your baby is how you experience the parental instinct. And so forth.

Nonhuman species ought to have evolved in response to different ecological pressures than humans, and thus possess different underlying instincts and different emotional and psychological lives.

Sometimes an SF writer manages to pull this off.

For well-developed nonhuman species, there’s no question which author leaps first to mind: CJ Cherryh.

1. Obviously Cherryh’s Foreigner series offers her best-developed alien species, the atevi.


The atevi are not all that different from humans physically, hardly more so than the standard bumpy-forehead aliens of Star Trek. But Cherryh handles their psychology and culture beautifully: their culture is actually not too alien, though very distinct from the specific human culture of Mosphiera on the atevi world. But the way numerology informs atevi language and modes of thought is great, and atevi instincts are certainly different enough to be a source of dangerous misunderstandings.

But the atevi are hardly Cherryh’s first successful alien species. Anybody who likes well-drawn aliens and hasn’t read her Chanur series should rush right out.


2. The Hani are based on lions, which gives them instincts and a culture that is complex, believable, and feels grounded in reality (because it is). The mehendo’sat are primates, but not human; the stsho are interesting; the kif are just scary — all the alien species in this series are well-drawn. My review of the whole series is here, so I don’t need to go into details again right this minute.

3. Okay, one more: I can’t move on from Cherryh without mentioning a story you may not have ever heard of: the novella “The Scapegoat”, which I found long ago in a used book store, but which might be findable if you poke around — Hephaestus Books did a collection that included it, according to Goodreads. Anyway, in “The Scapegoat,” Cherryh brings us into the middle of a long-drawn-out war that both sides want to stop, but that they can’t find a way to stop because of their psychological and instinctual differences. It is a beautiful story, but I warn you, it always makes me reach for the kleenix. This, I think, is one of the early works that shows Cherryh working out how to handle aliens with instincts that are different from human instincts, and working with the conflicts that arise from this difference. You can definitely view this novella as a precursor to the Foreigner series.

So that’s three titles. Time to move on from Cherryh and let someone else have the spotlight. So, in no particular order:

4. In Up The Walls of the World by James Tiptree Jr, we get the Tyrenni, a species that sort of resemble giant manta rays, but who ride the winds of a large gas planet’s atmosphere rather than being aquatic.


I read this one a long time ago, and I can’t even tell you. I loved it. It was one of the very first alien species I ever encountered. It took me years to bother reading the bits from the human point of view. Psychologically, the Tyrenni are actually very understandable and easy for the reader to connect with emotionally; culturally, they are quite distinctive from humans because their biology and environment is so different.

5. A far more current example of an alien species that evolved in a tremendously different environment are the Ilmatarans that we meet in A Darkling Sea by James Cambias. “On the planet Ilmatar, under a roof of ice a kilometer thick, a team of deep-sea diving scientists investigates the blind alien race that lives below. The Terran explorers have made an uneasy truce with the Sholen, their first extraterrestrial contact: so long as they don’t disturb the Ilmataran habitat, they’re free to conduct their missions in peace.”

So as you can see, we actually get two alien species in this story: The Ilmatarans which are VERY VERY DIFFERENT and the Sholen, which are obviously inspired by bonobos. Cambias handles both well. My favorite detail, because shows an instinct totally alien to humans, is the way Ilmatarans regard their children. They are plainly an “r” selected species, not a “K” selected species — they plainly spawn huge numbers of offspring, which they are utterly disinterested in unless they happen to want an apprentice, in which case they go out and catch a wild child, tame it, and teach it the skills they want it to know. Yet Cambias makes Broadtale a character the reader can easily emphasize with and cheer on. Here’s Jo Walton’s take on A Darkling Sea.

6. While on the subject of instincts that are quite different from humans, let’s mention the Oankali from Octavia Butler’s outstanding, disturbing Lilith’s Brood series.

Lilith's Brood

“Lilith Iyapo is in the Andes, mourning the death of her family, when war destroys Earth. Centuries later, she is resurrected — by miraculously powerful unearthly beings, the Oankali. Driven by an irresistible need to heal others, the Oankali are rescuing our dying planet by merging genetically with mankind. But Lilith and all humanity must now share the world with uncanny, unimaginably alien creatures: their own children.”

Okay, as you can see, lots of scope for conflict and tension and all that good stuff. What interests me most, though, is something that I’m not sure Butler did consciously: she gave the Oankali instincts which they are utterly unable to override. There aren’t any human instincts that can’t be overridden, perhaps because under most circumstances humans actually experience a certain tug-of-war from competing instincts. Thus soldiers can leap on top of a grenade to protect their buddies despite the survival instinct, and unfortunately some mothers can neglect or abuse their children, and if the culture offers enough pressure you can get the brother-sister marriages we saw in Egypt, and so on.

The Oankali can’t override their own instincts and in my opinion this is the single greatest source of misunderstanding between Oankali and humans. If you read this series, think about that and see if you agree. And you really should read it — it is brilliantly written because, you know, this is Octavia Butler we are talking about.

7) Also brilliantly written: A Fire Upon the Deep by Vernor Vinge

I’m not bothering to show cover, because the cover doesn’t show the Tine species at all — it’s a space cover. Which is fine, because this story is about a lot more than the Tines.

“Thousands of years hence, many races inhabit a universe where a mind’s potential is determined by its location in space, from superintelligent entities in the Transcend, to the limited minds of the Unthinking Depths, where only simple creatures and technology can function. Nobody knows what strange force partitioned space into these “regions of thought,” but when the warring Straumli realm use an ancient Transcendent artifact as a weapon, they unwittingly unleash an awesome power that destroys thousands of worlds and enslaves all natural and artificial intelligence.

Fleeing the threat, a family of scientists, including two children, are taken captive by the Tines, an alien race with a harsh medieval culture, and used as pawns in a ruthless power struggle. A rescue mission, not entirely composed of humans, must rescue the children-and a secret that may save the rest of interstellar civilization.”

So you see. As it happens, when I read this book for the first time, I barely paid any attention to the broader SF plot because I was much, much more interested in the Tines. Though telepathic aliens is a very common trope, the Tines are one of the only alien species with believable telepathy, because Vinge sets up “telepathy” with science rather than magic. How cool is that? The Tines are not that intelligent individually, but they form “group minds” with emergent personalities from groups of four or more individuals. There are so many consequences of this that I can’t even touch on the main points, but here’s one: Tine groups have to stay far enough away from other groups that they don’t blur together. And here’s another: they can change their overall personalities by adding (or subtracting) members of the group.

If you’re interested, here’s a review of this title from Kristen at Fantasy Book Café.

8. I used to say that the Tines were the ONLY believable telepathic group-mind species in SF, but now that’s not true! Because Ann Leckie pulled off the same thing, in a different way, in her outstanding Ancillary Justice. Breq used to be a starship with hundreds or even thousands of bodies spliced in (via Sufficiently Advanced Technology). Now Breq is . . . how to put this . . . a group mind reduced to one? As far as I’m concerned, Breq and the other group minds in this universe count as an alien species.

“On a remote, icy planet, the soldier known as Breq is drawing closer to completing her quest. Once, she was the Justice of Toren – a colossal starship with an artificial intelligence linking thousands of soldiers in the service of the Radch, the empire that conquered the galaxy. Now, an act of treachery has ripped it all away, leaving her with one fragile human body, unanswered questions, and a burning desire for vengeance.”

Ancillary Justice was the easy winner of the Hugo this year. I don’t know that I would hand it to a reader who never reads SF, because it’s a pretty demanding story. But anybody who loves fine SF should definitely read this, in the unlikely case they haven’t already.

9. It’s getting tough to choose! Only two spots left for a top ten! Let’s sort of cheat and pick aliens that aren’t *that* alien, in a sense (though quite alien in another sense): Startide Rising by David Brin.


In this book and the others in the series, Brin features “uplifted” dolphins, chimpanzees, and gorillas — animals bred for intelligence and now more or less integrated into the broader human society. In this universe, species never or almost never achieve sentience without being uplifted by another species — but no one knows how humans became sentience. However, that’s not the interesting part. In this context, at least, the interesting part is how dolphins and chimps remain true to themselves instead of becoming exactly like humans. Brin does this well, so the series is worth a place on this list.

10. And finally, after a struggle, I’m including Golden Dream by Ardath Mayhar.

Golden Dreams

H Beam Piper created the species with his Little Fuzzy and related stories, all of which got these beautiful Michael Whelan covers. But the novel I always liked best is this adjunct story by Ardath Mayhar, from the Fuzzy (Gashta) point of view. The events of Little Fuzzy are seen here, but from the other side and with a whole lot more about Gashta culture integrated into the story. I don’t know that the species is as thoroughly developed as some, or at least I don’t think it is as distinctive as some, but it’s still a delight to read.

In fact, it gave me a longstanding desire to kind of pick this idea up from the other direction: write an SF story where humans were long ago marooned on a world where they didn’t quite fit and their stone-age descendants rescued by really big aliens — aliens who think humans are so cute and charming. I actually do have about 80 pages of this written, so someday . . .

And that’s ten! Whew. It’s hard to stop, so:

11) One more, if you don’t mind: Mother of Demons by Eric Flint. Giant sentient mollusks? That’s hard to beat.


“An outcast with a perversion (she liked males); a great battle mother with an impossible task; a paleobiologist with a terrible sense of humor — they were all revolutionaries, but had never expected this. . . ”

Eric Flint does a great job setting up the biology and culture of his alien species. Some of the story is written from the human point of view and some from various alien points of view. I must say, when a human lifeboat carrying half a dozen adults and a hundred or so kids crashes on the planet occupied by two species of sentient mollusks, the dominant one in, if I remember correctly, the bronze age . . . well, it’s a great set up for drama. This is a faster-paced story, easier to get into than, say, A Fire Upon the Deep.

Okay, I am almost stopping there, but let’s have a handful of honorable mentions before we close. These are honorable mentions because I have one or another problem with the alien species or because the alien species is not all that well developed, not because there’s anything wrong with the stories as stories. I really like all of these.

Hellspark by Janet Kagan. The aliens are not that well developed; the thrust of the story is elsewhere; but it’s good.

The Sparrow and Children of God by Maria Doria Russell. I don’t believe in her alien species, which I don’t think could actually evolve. And some of the worst things I’ve ever read about happen in this duology. But still, it deserves a look if you love alien species.

Hero and Border Dispute by Daniel Kerns (Jacqueline Lichtenberg). I don’t believe in this alien species either, because I think a complex social structure is necessary to evolve intelligence . . . but if I were wrong and a solitary species could become truly sentient, well, it might look very much like this. These books are great fun to read and it’s a huge shame they didn’t take off well enough for the series to continue. I wish Lichtenberg would self-publish any sequels she has sitting around.

Ender’s Game by Orson Scott Card. I dislike magic telepathy in science fiction. I especially dislike magic telepathy and hive minds. Ugh. Cherryh did the hive thing better, at least better for me, in Serpent’s Reach, but I already have three of hers listed that I liked better.

Speaker for the Dead by Orson Scott Card. I totally don’t believe in this ridiculous genetic blending animal-plant lifecycle stuff. Evolution can’t produce impossible results. Faced with the biological challenge presented in the evolutionary past, if nothing had already been resistant, everything would simply have become extinct. I dislike magic biology, so this didn’t make the list. The story itself is good, though.


Elaine T adds: “In case anyone cares, it [“The Scapegoat”] is most easily available these days in THE COLLECTED SHORT FICTION OF CJ CHERRYH, which all CJC fans probably ought to have anyway. I read it first in ALIEN STARS ed by Mitchell & published by Baen, and which is probably easy to find used.” Thanks, Elaine! I didn’t know that, and I definitely, but definitely, recommend that everyone look up “The Scapegoat”, which truly is a beautiful story. I also have it in ALIEN STARS, but when I was writing the post, I was doing it from memory and didn’t remember the title of that collection.

Mary Beth adds: “Anyway– aliens! Yes, Cherryh is my first thought when I think of aliens done well in SF, although I’m shamefully far behind in the atevi books. The Cuckoo’s Egg is another good example of her alien books (and I see its inspiration quite heavily in Karin Lowachee’s Warchild, which has the same central concept of an alien species raising a human child to be both an assassin and a bridge between the species). Actually though my TRULY favorite aliens in Cherryh aren’t even really sapient: they’re the nighthorses of the Finisterre books, and really just that whole, freezing, terrifying world. I would trade a dozen atevi books for one more Finnisterre novel. (Maybe I just really like carnivorous horses. I’m currently in the midst of a belated reread of Maggie Stiefvater’s The Scorpio Races, after all.)”

The Finisterre series isn’t my favorite, it’s a very claustrophobic world, but I do wish Cherryh would go on and actually *finish* it. And now I really want to go re-read The Scorpio Races.

Please Feel Free to Share:


Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top