Buzz
To clarify from the beginning, this list is neither all-inclusive nor an attempt to rank the ‘greatest’ extraterrestrial species. I truly believe there are likely far more alien races in the universe than what science fiction has managed to imagine (and we haven’t encountered any of them yet). However, the genre has certainly put forth an impressive effort in speculating what these beings might look like. This list, then, consists solely of a selection of aliens I have enjoyed getting to know within the pages of books. Some are enemies, others are allies, and some fall into neither category, being misunderstood or decent despite their appearances. To narrow the scope, the following criteria apply: Only races featured in 'books' (no short stories or visual media). The book must be enjoyable even if the aliens were not as intriguing. The aliens must be well-developed, so you would have a solid idea of what to expect upon encountering them. They must be unique and unforgettable. What follows is a list of aliens I feel I ‘know,’ in no particular order.
15. Aalaag
Difficult for humans to pronounce, with a deep glottal stop after the first 'A,' the Aalaag easily took over Earth, setting the stage for Gordon R. Dickson's 1987 novel, Way of the Pilgrim. Within their own culture, the Aalaag are considered highly just rulers — any mistreatment of their human 'livestock' by one of their own is regarded as a grave offense. However, they demand strict obedience and adhere to a rigid code of conduct that clashes with the human spirit. Ironically, the Aalaag are themselves a conquered race, having fled their home worlds after an unnamed but overwhelmingly powerful enemy destroyed them. They are, at their core, warriors — tall, proud, and each bearing a collection of personal weapons, with a Spartan outlook on life. Every Aalaag believes that duty is the highest virtue, and all their actions are aimed at one day reclaiming their lost worlds. The races they conquer are used to gather resources to further this ultimate goal. The protagonist, Shane Evert, is a talented linguist who leads a translator-courier group in service to the alien leader, First Captain Lyt Ahn. The title of the novel refers to the Pilgrim, a universal symbol of the human condition, which later comes to represent the emerging resistance movement. Immersive, deeply human — at times truly captivating — this novel is Dickson at his finest, and that is a high standard indeed.
14. Psychlos
Forget the dreadful John Travolta movie adaptation. Forget whatever preconceived notions you have about L. Ron Hubbard, the founder of Scientology. Instead, dive into his massive (1,066 paperback pages) 1982 novel, Battlefield Earth. This is space opera in its purest form, as space opera should be. The Psychlos don’t just conquer planets. They don’t just conquer galaxies. They conquer entire universes. They possess the secret to instantaneous teleportation, a key part of their operations. One of their largest enterprises is the Intergalactic Mining Company, which sends indigenous populations back to the Stone Age before systematically stripping their planets of every last mineral, almost down to their very cores. And, to make matters worse, the Psychlos relish cruelty, finding it “delicious.” The crooked — even by their standards — Security Head of Earth, Terl, is plotting to get rich by “training” native humans to do illegal mining for him. A stellar job of characterizing both aliens and humans, all within a story that moves at such a fast pace, you’ll hardly realize you’re reading. Special mention goes to the Selachees, another alien race in the novel, which plays a crucial role in the plot.
13. Thranx
Alan Dean Foster has written several novels set within the Human-Thranx (Humanx) Commonwealth, though most focus on familiar characters like Flinx and Pip, often leaving the Thranx in the background. However, one book stands out for its deep dive into Thranx culture and the story of how humans came to form a partnership with them. That book is 1982's Nor Crystal Tears, which is largely told from the Thranx perspective. Everything in this novel feels just right — by the end, you find yourself rooting so hard for the insectoid Thranx to form an alliance with humans that you'd easily spot any misstep where Foster doesn't portray them true to their species (even though there’s room for individualism within the race). Foster handles the Thranx flawlessly, and I have to admit, I've always had a soft spot for praying mantises.
12. Martians
In Fredric Brown’s 1955 novel Martians, Go Home, the Martians are quite literally little green men. But what they truly are — first and foremost — are complete jerks. Their primary occupation seems to be being obnoxious. They invade Earth by the millions, arriving literally overnight, speaking English with a Brooklyn accent, and proceed to make life miserable for everyone. The results are often disastrous and sometimes fatal. They have the ability to teleport anywhere, and though they can't be touched, they're solid enough to cause car crashes and airplane accidents by the thousands. Their favorite pastimes include revealing your personal secrets, disclosing national defense information to other countries, and pointing out all human flaws — basically anything to be as irritating as possible. This book is widely regarded as a genre classic, and I’ve never met anyone who read it and didn’t enjoy it.
11. Pequeninos
Speaker for the Dead, Orson Scott Card’s 1986 sequel to his internationally acclaimed Ender’s Game (which rightfully earned its place on JFrater’s list of science fiction for non-science fiction readers), won both the Hugo and Nebula awards — marking the first time an author had won back-to-back honors. While Speaker differs significantly in tone, setting, and themes, Ender remains the central character. Some may argue for the Buggers or Jane as a more iconic alien race, but it is the nuanced portrayal of the pequinos society that earns the spotlight here. Particularly because, much to Ender's frustration, the challenges of cross-species communication take center stage again as humans try (unsuccessfully) to understand the pequinos without disrupting their natural evolution. The novel is poignant and thought-provoking, with a fascinating exploration of comparative religion — though don’t let that turn you away, as I, too, was never interested in the subject but still found the book incredibly captivating. Notable concepts such as framling (humans from other worlds), ramen (non-humans we treat as if they were human), and varelse (non-humans with whom communication is impossible, like intelligent viruses) should stay with us when we eventually encounter interstellar beings.
10. Overlords
Arthur C. Clarke’s 1953 masterpiece Childhood’s End is a staple in science fiction courses around the world, offering a unique take on alien intervention. The Overlords, though conquerors of Earth, bring only positive changes, improving life for everyone and solving many of humanity's ongoing problems. They do so from their massive starships that hover above major cities, observing mankind from a distance. Over time, humans adapt, as they often do. However, the Overlords remain hidden for fifty years, and their reason for doing so involves the Jungian concept of racial memory. No spoilers here, but this element is one reason the novel is such a favorite in academic circles. Of course, the Overlords’ true motives are eventually revealed, and the revelation can best be described as deeply poignant.
9. Fithp
Although Larry Niven didn’t write for money, Jerry Pournelle certainly did. Yet it doesn’t matter, because both are iconic science fiction authors, no matter what they were eating at the time. Together, they form one of the genre’s most successful writing partnerships. An exemplary piece of their work is the 1985 novel Footfall, which was so popular that even readers who didn’t typically indulge in science fiction were picking up Niven/Pournelle books throughout the 80s, eagerly awaiting each new release. In Footfall, the Fithp are essentially depicted as elephants in space. Whereas humans are an individualistic culture and ants live in colonies, the Fithp embody a herd mentality. This premise is explored with exceptional depth — and, true to their nature, the Fithp simply don’t grasp the notion of diplomatic compromise. For them, the world is black or white: you either dominate, or you submit. The book also delves into the complex internal dynamics of an intelligent herd engaged in conquest, and it does so with remarkable insight.
8. Drac
Ok. So here’s the story: A guy publishes a novelette that wins the Nebula, mere months after publicly denouncing the very awards! Then, it wins the Hugo and the John W. Campbell award, marking the first time anyone has won all three in the same year. Sounds like a big deal? Kind of. Enter Hollywood with a somewhat overlooked film starring Dennis Quaid and Louis Gossett, Jr. (Gossett even received a Best Actor nomination, despite the film’s lackluster reception). Suddenly, Barry B. Longyear is a major name in science fiction, all thanks to 1979’s Enemy Mine. Dracs and humans are locked in a brutal war. When one human pilot and one alien fighter pilot are stranded on a hostile world, they must work together to survive. The twist? Dracs are hermaphrodites, and Jeriba doesn’t need a partner to reproduce. Spoiler alert: After an untimely death, the human is left to raise the alien’s offspring. Both the book and the movie focus on the deep, emotional bond between one human and one alien. If you approach this story with the right mindset, you’ll shed tears. You will come to know the Drac deeply, especially if you’ve read the book and watched the film. The Drac earn their place here because they fit the criteria; I own many of Longyear’s works due to the sheer emotion in Enemy Mine, although I find much of his other writing a bit hard to enjoy.
7. Fuzzies
H. Beam Piper secured his legacy in science fiction with the release of 1962’s Little Fuzzy. Words like “delightful” and “charming” are often used to describe the book, and it’s easy to see why. The Fuzzies are undeniably cute and cuddly. However, the novel delves into a deeper question: what defines sapience? Are these creatures merely animals that we can dominate, or are they sentient beings deserving of respect? This moral dilemma — exploitation and even murder — is explored throughout. Several sequels followed, some written by other authors, but none have captured the magic of the original.
6. Groaci
It’s uncertain whether Keith Laumer is more famous for his Bolo series or for his James Bond-like assistant diplomat character, Jame Retief. Most likely, the latter. Laumer’s stories and novels spanning several decades have gained popularity. These humorous and action-packed tales showcase human cleverness when dealing with diplomatic blunders. In most of his works, the mysterious alien activities are secretly orchestrated by the Groaci, a race of skilled diplomats who, despite their ability at negotiation, struggle with straightforward dealings. Though their portrayal is somewhat one-dimensional, the Groaci are formidable unless restrained. The books are filled with puns, light-heartedness, and wit, but the Groaci’s diplomatic prowess is undeniable. Fun, yet hardly without flaws.
5. Ythrians
Poul Anderson is undeniably one of the titans of American science fiction, with his impressive body of work. A prolific writer, Anderson penned numerous short stories for the magazines of his time. His so-called ‘Future History’ shares similarities with Robert A. Heinlein’s concept, though Anderson’s version is far more fragmented. Many of his tales are set in the backdrop of the Polesotechnic League, a fictional 4,000-year-long history of human interstellar exploration. The League mirrors 19th-century capitalist practices, though often in a veiled or even unsubtle way. As for the Ythri, 1978’s The Earth Book Of Stormgate doesn’t strictly meet the criteria, as it’s a collection of stories rather than a novel. However, Hloch, a scholar-historian, introduces each story, and his interlaced commentary provides valuable insight into Ythrian culture. This makes the Earth Book a fitting medium for including the Ythri in this list, even though they appear in other works by Anderson as well.
4. Hroshii
Describing these beings without spoiling too much is tricky, but here’s an attempt. More than half of Robert A. Heinlein's 1954 'juvenile' science fiction novel 'The Star Beast' unfolds before the word 'Hroshii' even makes its appearance. But once they show up, they're incredibly strong and have no interest in negotiation. They’re on a mission to find someone, and they refuse to accept any refusal. The person they are searching for also has trouble with the word 'no.' This person is not intentionally rebellious, nor do they wish to cause harm—just very literal about following instructions and perpetually a little hungry. 'Lummox' is more than just a person, they’re a friend!
3. Yilane
Another famous race that stands out, and one can only hope that someone with a decent budget will bring Harry Harrison’s 1984 masterpiece, West of Eden, to the big screen. The book led to a series of sequels, each with a slight drop in quality, but it remains a remarkable example of intricate alien design. The Yilane, though not technically aliens in the traditional sense, are part of an alternate Earth evolution. Humans are still in the hunter-gatherer phase, while the Yilane are small, intelligent, upright reptiles descended from dinosaurs. Their society is matriarchal, and their technology revolves mainly around manipulating biology. They grow plants and animals with specific traits that allow them to serve as tools, from microscopes to boats and even living blankets. The Yilane live in tropical regions, whereas humans inhabit temperate zones. However, as climate change looms, the two societies inevitably collide, leading to conflict. Kerrick, the human protagonist, has a unique perspective—he was captured by the Yilane in his youth and raised among them. This experience allows the reader to understand the Yilane culture in depth without relying heavily on exposition. As Kerrick learns about their world, so do we, gaining insight into a culture that is entirely alien, yet presented through engaging storytelling. While Harrison's other works vary in quality, with some being mediocre and others quite good, he undoubtedly achieved greatness with this one.
Contributor: Grubthrower
2. Chtorrans
If you’re not familiar with David Gerrold, you’ve likely heard of at least one of his contributions — namely, the Star Trek episode “The Trouble With Tribbles.” Over the years, he has written a variety of short stories and novels with varying degrees of success. But in 1983, he published A Matter For Men, the first volume of a series known as “The War Against The Chtorr.” The Chtorr are most often represented by the infamous “worms,” but the true story is about a whole biosphere that attempts to take over Earth. Several books followed, and thankfully, some of the later installments are just as compelling as the first. These books must be read in sequence, as the Chtorran infestation escalates, and humanity’s response evolves. This series almost stretches the definition of what constitutes a “person” — while it’s hard to imagine a Chtorran worm as a “person” in any conventional sense, one might consider it a “God,” but not a human-like being.
1. Forhilnor
Quite remarkable how human-like they seem, despite being essentially massive spiders. Robert J. Sawyer, a prominent Canadian author widely known for his work in “hard” science fiction, introduced this fascinating race in his 2000 novel Calculating God. Although the story revolves around the Forhilnors' arrival on Earth and their interaction with a human paleontologist, the aliens are somewhat passive participants in the plot. Sawyer uses this encounter to explore profound themes like creation, cosmology, and the very reason life exists. Nonetheless, readers would certainly enjoy having Hollus as a dinner companion, and many would consider them a true friend. This fits the criterion of understanding these beings at their core. To digress: Imagine three close friends—one a staunch fundamentalist certain of their salvation, another an agnostic who believes in God but is uncertain of the details, and the third an atheist who adheres strictly to chemical processes. They’re all good friends, and Calculating God is the perfect book for them to discuss around a campfire.
