For one, rabbits, which are “crepuscular”, which means they are most active at dawn and dusk. Not quite nocturnal; instead, they’re awake at the beginning of the moon rising.
As Heejin is the first member of LOONA, she’s much like the rabbit as she is ‘awoken’ at the beginning of the lunar cycle, which is what the Loonaverse orbits around. Rabbits are also linked to the idea of rebirth- this brings in the ideas that Heejin is here at the ‘birth’ of the universe. But why rebirth, and not birth? (All in due time!)
However, there may be another reason for her animal being a
rabbit, and it has to do with the origins of the Loonaverse...
There are many parallels between Heejin’s “Vivid” music video and the story of “Alice in
Wonderland”. For example, her animal is the white rabbit, and there are multiple allusions to the story in the music video.
However, Heejin is clearly not Alice- she’s God of this new world, so any similarities to the story were probably made by her, since she started with a blank canvas of a world. But these allusions may signal more about Heejin’s character and origin story. Maybe Heejin is from our normal planet Earth, and fell down some sort of ‘rabbit hole’ or wormhole taking her to the Loonaverse. On Earth, she must have known the story of Alice in Wonderland and therefore when she lands in this new world, her mind makes up this story of her falling into her own “Wonderland”.
I’m not saying that the Loonaverse is Wonderland, or that Heejin is Alice- the Loonaverse is its own place. This simply sheds more light on the possible origin of the Loonaverse and explains the Alice in Wonderland imagery throughout the ViVid music video beyond it being a cool MV concept (though that might be all it is).