I think it will be hard to implement, but having creatures that protect their territories brings a whole new level of immersion. Basically, if a wolf wanders into bear territory, they both would engage into combat.
This is good. Then it won't feel like the entire universe is out to get only you. It'll simply be nature being nature.
If a Raccon (the space dwelling species of Raccoon)/ Red Panda war is going on in the BG of the main story... Then yes, Don't I have great editing skillzzzzz?
Hmm intresting, would the wolf try to retreat after getting critical damages, would it walk slower, would it bleed to death? Also, it worth mentioning that wolfes hunt/live in packs...