-bump for lively world-
I'll expand on my idea for engaging mob a bit.

Have mobs engage in combat with each other. It doesn't necessarily mean that they will lose hp or anything, but an ai where mobs of the same family, or loner in a camp, would go up to each other and have a little fight animation. What would be cool is if we attacked one the other mob will fight along side us.

Have better movements, not just random. Have some of them be in a small group that travel together. If one is attacked the other will flee and join another group, or they'll just break off.

A bit more animation. Don't just have standing and moving animation. Add some extra idle animations. Perhaps a marmot chases its tail, crabs can clean their eyes, dodos can run and flap their wings pretending to fly, etc.

Interact with weather. Maybe a sheep can shake its fur dry once in awhile in the rain.

Mobs should definitely be more than just higher poly counts & high res texture.