You have been born into a magical world in which at age 13 you are transformed into a magical creature. You could be transformed into a mythical beast, a regular animal or simply another type of human-like creature (a dwarf, an elf, a giant). You gain the powers of the creature that you are transformed into. If you were a cat you would have the choice to grow fur or cat-like ears and your eye color would change. You would also be silent when you walked and you would have been able to become invisable at will.
You choose what you become transformed into and your destiny is your choice.
BIO: name/age/looks/family/gender/crush/what animal transformed into/powers/other