At the risk of sounding salty... I actually hope they stick mostly to real Earth animals (the last ice-age to present). I kinda don't want Chronicles of ARK-lyria, where dinos and fantasy creatures run around every corner of the surface of the planet.
I'd love to see Red Pandas as a common pet for Kypiq. Or Sugar Gliders.
If and when I encounter a chimera style creature I kinda hope it is a heart stopping moment not ho-hum. I wanna be so bored by the ordinary fauna in the mountain pass that when I hear a shrill, piercing shriek and the lightning bolt from the storm drake hits me that I almost faint.
The devs have clearly shown a desire to blend real Earth creatures into new and interesting combination (Canis Rabbit, Trison and Ursaphaunt), I just hope that these new creations are mixed into a plethora of familiar animals to help them feel like they naturally integrate with the ecology of Elyria, rather than jarring the player out of immersion each time they see a single animal.
I suppose that all being said, I'd like it if the biomes are hostile to the unwary travelers and adventurers.
I'd love a force of invaders plowing into a Kypiq protected forest to find themselves overrun with harmless looking beetles until they realize that the beetles are leaving highly poisonous egg sacs in their water supply. Something every Kypiq child would already know to look for...
For the above reason I really hope that SBS actively avoids telling us about ANY of the flora and fauna. Let us learn from the NPCs that we start around. Another reason to engage with NPCs at launch.