Changeling

This race has the unique ability to take on the shape of a living thing. An animal or a plant. These people are born humanoid, but then they gain an affinity to that creature when the time is right in their life. They must study the creature they want to become, and become of it - in sync with the lifestyle, their spirit.

Often, a changling will choose their animal and leave their tribe and family to go on their journey for several years—sometimes even longer depending on the person, and the animal/plant they are gaining their affinity with. They live with that animal, living as it would and eventually become it.