Meris

Meris, the spirit of the forest, was being hunted by an ash demon. The goddess Tala blessed the creature with a man form to hold weapons and gave the Shifter a spear to defeat the demon.
With its last breath the demon cursed the spirit with formlessness, so it would never be able to fully return to its beast self nor retain a man form. At night, the beast form takes power from the light of the moon, but during the day it is easier to suppress.
Meris is the mother of the shifter race, and her children bear her burden.