The insects from Enders game are the standard to me. They can’t communicate with humans and structures built by them cause humans to feel uneasy. There are examples all over, but the key point is their language is so alien to us as to be indecipherable.
It’s been a long time since I read them, but I recall several of Robert Forward’s books having very alien aliens.
Yes he is an aspect of the universe, however I was going by alien as a being not of origin on Terra. But you are probably right that as part of the universe pre Big Bang, Galactus is not an alien as we normally think of an alien.
As a truer alien the living clouds on Jupiter from Arthur C. Clarke’s 2001 series. Non sentient but still living. I had always felt bad when they were destroyed when Jupiter became a star.
The Titans from John Varley’s series, Titan, Wizard and Demon. They were living space habitats the size of a small moon. He tried to make their motivations out to be non-human but failed pretty badly.
In the Sector General series by James White one comes across alien species of many varieties , each requiring different environments and having different physiologies . They are treated by a multispecies team of health care workers. Species range from insectoid , piscine , humanoid to caterpillar like and radioactive beetles with a group mind. IIRC there may also be a wheel like creature which needs to rotate constantly to maintain its circulation . There is also, I think, a sentient planet.
Seems to me the most alien aliens would be the ones so incomprehensible that it would not only be impossible to communicate with them, it would be impossible to comprehend their motives and relative frame of experience.
Peter F. Hamilton’s Commonwealth Saga (Pandora’s Star and Judas Unchained) has some of the most alien aliens I’ve read. Wikipedia’s description:
They seem like the kind of alien where there’s no possibility of real communication, because the world views of the two species are just too freaking different. They’re terrifying to me.
Several stories from Harlan Ellison’s “Dangerous Visions” anthologies would do. “Flies” by Robert Silverberg does not even describe the Golden Ones other than that they are not of protplasm. They are known by the actions they took and the impact it had. Another one in “Again, Dangerous Visions” by Gahan Wilson, whose title was an inkblot, has an alien that is that title, a two dimensional being appearing to us as an inkblot on and eventually taking over the page.
For a combination of completely alien and fully realized, you can’t beat *Octavia Butler IMO. Her Imago series is excellent. There’s also another piece by her, a short story, I think, in which the aliens are collective creatures that resemble bushes and communicate with humans tactilely–I can’t think of the name, though. Anyone know it?
Surely the Piggies from the sequel Speaker for the Dead are even more alien. Another excellent example of truly alien beings who are nevertheless fully realized characters, in fact.
The Tines are also featured in depth in his book A Fire Upon the Deep. It also includes some tentacled aliens who came from the ocean and like to go back and sway in the tides for years to think, some humanoids with butterfly wings and some other aliens that only communicate through an interstellar internet are mentions as being “cloud beings” or things like that. It also has races of aliens that have transcended into sort of supernatural powers that can’t really be understood by those that haven’t transcended.
His other book A Deepness in the Sky features intelligent spiders-type creatures that are basically going through the same scientific revolution that we went through in the 1900s.
IIRC, he was chided for both: not writing sex, and not writing aliens. So he’d do sci fi with humans in the not-so-distant future and their increasingly humanlike robots, or humans in the far-distant future with their interstellar civilization built around psychohistory, or humans going all over the place with time travel, and all of 'em pretty sexless – and so he took up both challenges simultaneously.
There was a TNG episode that attempted to explain why so many aliens and humans were so similar and compatible. Apparently some ancient aliens mucked around on Earth, the Klingon homeworld, Vulcan, etc and inserted stuff into the various races DNA.
As for very alien aliens… how about the Quintessons, from Transformers the Movie. Five faces on one head/body, with a bunch of tentacles for limbs. Oh, also they are living but also mechanical (as this was the Transformers movie).
Tracked it down, it’s s6 ep20, The Chase.
That’s all? If she were not dead, I would kill her.
Two contributions: Pierson’s Puppeteers, from Larry Niven’s 'verse. Physically very different from humanoid - three legged, asymmetric, brains not located in their heads. Personalitywise, not so much - cowardly Magnificent Bastards. Turned up to eleven.
The second is much more like what you are looking for: the creatures who created the waterspouts in Heinlein’s Goldfish Bowl. You never see them, you never get a hint at their thought processes or motivations. They are so far beyond humanity that they aren’t even aware of us.
Admiral! There be WHALES here!
Animation is not subject to the same restraints as live-action, so I think a good candidate would be Yivo, from the Futurama movie “The Beast With A Billion Backs.” Although his way of thinking wasn’t too alien (he wanted to experience sex and love, but with every being in the universe simultaneously), his appearance was suitably bizarre. He was an immense many-tentacled being made from electomatter that couldn’t live in our universe, but he could provide a habitat for everyone from our universe to live on him.
A Centauri with a bad hair day?
Anyway, some very good suggestions so far. Kepp them coming!
Reedman from Transformers: Revenge of the Fallen is pretty damn alien. He’s vomited out by a robotic jaguar which was pooped out by a metallic tentacle monster raping a satellite, and he starts out as a collection of tiny little metallic spheres. Then the spheres form together, creating what is basically a metallic, paper-thin, razor-sharp praying mantis. A really scary and alien design.