All around the world, sightings of anthropomorphic animals, sometimes called Zoo Men, have started popping up.
These anthros are born to normal animal parents and look like them as well, though they are much more intelligent than other members of their species (to the point of having a limited understanding of human language if they listen long enough), show behavior that goes beyond instinct (like a cheetah running for fun instead of just for hunting), and their faces being able to convey human-like emotions. They may grow up realizing they are different and feeling isolated as a result. When the animal reaches adulthood, the body mutates to its full potential. They gain full human intelligence, the ability to walk on two legs, opposable digits, and the ability to speak. They keep their animal features and senses like night vision, above human smell, and the ability to fly for those with wings.
As more and more Zoo Men pop up, they start to form communities and fight for their rights as sapient beings. The gene that mutates these animals can be detected when reading genetic material from a DNA sample.
This story follows one such animal beginning their transformation into a Zoo Man.