Alright, I'm late to the party, but I'm psyched for this. It reminds me of a book series I read, back in junior high. Except this story has humans and mutations involved. 

What about marine creatures: Dolphins are good?
Sharks are evil?
Orca's depend on the individual whether they are good or bad?
Also would there be seals, otters, eels, crabs, whales and octopus? 

I'm thinking about playing a Raven and an Otter if they would be in this story.