I see, so there would be like small settlements where the 'houses' are not too sturdy in case the inhabitants need to evacuate quickly, and there are places that's basically animal 'towns and cities' that will have sturdier buildings and defensive structures?

The idea of hybrid creature is actually pretty good. In that case, how many years from the mutation will this RP take place on? Like only a few decades from the radiation (or from the moment the animals starting to band together) or will it be like say 100 years after the 'Incident' where things within and between factions are more settled (everyone knows where the others stood)?