Play for me, mortal...

They used to be dinosaurs, but that's not important right now... ;-)

"Winged things"?

Makes sense that birds are not an all too familiar sight undergrounds...

"feather-bats"

ha ha ha that's so true that birds are totally alien

Smol, they are for "waste management"...

Assume they are like bats. That makes it easier, lmao. He probably did encounter bats, right?