@00pi
I'm afraid I've missed them in my sci-fi readings.

@00pi
Well except for So long and thanks for all the fish.

@FireMonkey I am not too familiar with animated Star Wars, but it is my understanding that those whales made their debut there, and exo-life had a precedent with the asteroid monster in Episode V. Star Trek had them on Discovery. Farscape takes place on one. Doctor Who had cities built on them. It's a recurring trope, appearing in video games, on screen, in writing.

@00pi
Hmmh, missed it all. Now, elephants on a turtle, yes, but I missed the whales in trek, who, and 'scape. Will have to revisit.

@FireMonkey My definition of space whale may be a bit overly broad, but "Leviathan" certainly seems to be meant to evoke whales in Farscape. In Trek:

https://memory-alpha.fandom.com/wiki/Gormagander
and arguably
https://memory-alpha.fandom.com/wiki/Gomtuu

In Who:
https://tardis.fandom.com/wiki/Star_whale_(The_Beast_Below)