The Darwin Chronicles, Book One: The Mountain Ranges

Ah, yes. The humans. They have the power to morph into any animal at will. Just regular animals. Dogs, cats, birds, reptiles, sea animals. But some lucky few can also morph into legendary creatures. Phoenixes, dragons, those kinds of mythical creatures. The humans live in tribes, peaceful tribes. Sure, of course there are a few battles and skirmishes here and there, but no war. No, the real trouble lies within the other creatures that dwell within our world.

Here's how the world works. Each tribe has their own territory. The borders are mainly there so that each tribe has enough land to survive, and the population density is the right number so that they can defend themselves from monsters. Each territory has one city, right in the heart of them. The tribes help each other, trading with each other, aiding each other in times of trouble. Everyone is a warrior, unless their age or health prevents it. The age during which a person is a warrior is, in average, about fifteen and a half to forty-five years old.