"Peep, peep? You don't even know how an eagle cries! It's 'screech'—!"
The eagle went, "Tweet, tweet, tweet-dada."
... Forget it, sometimes it's just like dealing with a nutcase...
Ahem, anyway, according to these years of Chen Xuantian's research,
this thing is the projection of a Kun on the other side of the string.
In short, a Kun is still a Kun, but on Tie Dan's side, it's a fish, and on his side, it's a bird—it changes depending on the dimension you're observing from.
As for how it grew from a little chick to a gigantic chicken, no, a huge eagle, it's because it needs to eat.
Hmm, after years of communicating with the Kun, the Outer Heaven Void Swallowing Star Lord couldn't survive on just drinking water and eating barbecue; its main course is 'Void Stars', stars being those balls of pure light and heat, and void being just that, 'void'.
So Chen Xuantian refined the remnants of the aged Kongsang Daosist into 'void' and fed them to it, and naturally, it grew larger.
