Supernatural & Animal: Just as some humans believe that there is a God, in this world its is believed that the God got angry at the humans and placed a curse, transforming all humans into animals. the transformation into an animals depends on what kind of personality that's human has.
Survival: Due to this transformation they all had to find a way to adapt to they're new body and environment e.g a human fish wouldn't be able to live on earth.
Evil Villain: as years go by there was an evil animal that decided to take the place and rule the city. as once a human this character was a wanted criminal but as the transformation took place this human became a predator sharp claws, huge no other animal could stand up to him or even look at him.
Hero: Before the transformation this character was a trained solider. trained to handle fear, the ways of stealth and combat. this human was transformed maybe into a black cat an animal that can be strong as well as stealthy. this is the character that will fight the villain and bring him down in order to retain peace.
Sidekick: For the sidekick I was thinking it could be something smart, knows its way around and also about to handle itself in a fight. I was thinking maybe a dog with geeky glasses or mouse.