Stories with strong elements of xenofiction, speculative biology, or a scientific approach to magical systems. Genre-wise I tend to favour science fiction and science fantasy with elements of horror.

I've mostly added the first book (or collection) to this list. Several of the novels have sequels that are also worth checking out.

Usually YES: Animals, aliens, AIs and robots, mythological creatures, eldritch and divine beings

I put a strong emphasis on the non-humanness of the narrative. If it looks like a human, but doesn't think and perceive the world like one, it might still be included in the list. Fae and immortal or undead humans might be an example of this in the hands of the right author.

Usually NO: Magical humans, vampires, green space babes and rubber forehead aliens, humans with animal ears, tails or wings, furries and funny animals, most shapeshifters

If it looks like a non-human, but functions as a human proxy or a simple metaphor for "the outsider" in a particular universe, I'll exclude it. I don't consider rubber forehead-aliens, the X-Men or Donald Duck xenofiction, for example.

Other xenofiction lists on Goodreads
Monster/Animal/Non-human POV
Through Another's Eyes
Non-Human Protagonists