Some are born with innate powers tied to specific animals, demons, dragons, or even aliens. These are known as Shifters, and they contain their powers by fusing them into special magical stones which allow them to shift into their monstrous form.
At character creation, the Shifter determines what animal/creature they shift into which can't be changed after it is chosen. When choosing what animal they'll shift into, they restrict themselves to the stones which are associated with their animal. Here is the list of different Shifter bloodlines.