I came across a mythological belief a few weeks ago, I believe in a Sam Kriss piece (1).
It centered around a bird (a swan or goose, I want to say?) that ceaselessly flew (in a primordial void/chaos?) - the universe had started with its flight and would end with it (the bird exhausted/landed/perished?).
I think it might have been a Pacific islander culture, or something else relatively obscure like that. I'm almost confident it was a shamanistic belief.
I've trawled through wikipedia but had no luck. (It is not the Huma bird, which is said to never land, but lacks the connection to the universe's existence. Neither is is the Roc, Simurgh, or Ziz).
- (I remember thinking the reference might have been a Borgesian hoax, but subsequently finding a wikipedia page that corroborated its existence.)