[quote=jeray2000]
1. I excluded other large animals like rhinos because they don't live in the Americas, or they were among the many trying to create feudal holds in South America. 
2. Also, most bugs living within the Human Empire boundaries are allied with them, because otherwise it would be similar to nuclear war. Humans use poisons, bugs spread diseases, no one wins. The bugs outside of the human empire are with the UAR. 
3. But which animals are the bad guys again, and where would their territory be? 
4. I was thinking maybe the plot this revolves around could be a kingdom rising in South America where several evil animals united to destroy the humans and the UAR.
[/quote]
1. You mean Africa, right? The rhinos would be trying to do so in Africa and may send mercenaries over to the Americas for whatever reason.
2. We could say they can no longer spread diseases. Something about all the mutations going on.
3. Snakes, spiders, rats (mice would be the good ones), crows, vultures, etc. All the animals with a bad rap. I'll think of their possible territory.
4. Hmm...

[quote=Wreck]
Understandable, but I've reached a conclusion with Important, I believe. I'd think species that have a reputation for being wicked, like snakes and other reptilians, could be the antagonists that want to take the deserts of North America for some reason or these reptilians see themselves as the 'most powerful' species and wish to destroy/enslave the UAR.
[/quote]

The bad guy animals wish to conquer everything, not just the good guy animals. Probably.