You can see some of my world-noodling about aliens that don't need to breathe at: https://rznicolet.com
I've been plotting a series of hard sci-fi novels entirely from the point of view of very not-humanoid aliens. In this case, hard SF = all real physics except for FTL. First manuscript complete. Humans not included in the main series, except as passing footnotes. Let's just say that when I originally started, the pandemic had me feeling a touch misanthropic. We'll see when/how I actually publish these.
I write fantasy stuff, too, though since the blog is relatively new, I haven't started adding that in yet. I'm currently wrapping a sequel to a finished fantasy work (again, publication approach TBD) before switching back to relatively hard sci-fi.