I think in general there needs to be a ton of different animals, and i would like there to be some pets too maybe.
The animal selection in the current version (pre-update) isn't terrible, but i feel like there should be like hundreds of different types. Would also be nice if, for example, a cow could be bigger or smaller randomly, and would give different amounts of food related to size.
In general i'd love for there to be extremely rare animals, and certain animals should spawn in groups and some shouldn't, like say a fox shouldn't. Also i'd love for you to just remove the background bird sounds and like add birds because who doesn't like birds? Anyway the point is not to have like hundreds of animals in your view at all times, but to have a large variation for every biome, so you're always finding new animals.
I would mainly like tropical birds in a like rain forest biome, fish in a river, lake, and ocean (i don't know fish, but you could make it so a real fish comes up and bites the lure when fishing), and frogs near rivers, ponds, and lakes (maybe a new marsh biome?)
I love this game, and it needs combat, but i do think this could greatly improve the experience, and make it a bit more interesting if you found some insanely rare animal.(mabye an animal book that charts all the animals you've seen? I would love that.)