Bagi, the Monster of Mighty Nature(1984)

Daishizen no Majuu: Bagi

Ryo is sent out by the people of a village to kill the monster which has been attacking the villagers. It is rumored that this monster is a cat-woman named Bagi. As Ryo waits for the monster to come to its watering hole, he thinks back to how he first met Bagi as a kitten who learned how to write, and later reenters his life on a quest to discover who and what she really is. But now she has gone wild, and as the time of her arrival approaches, he strengthens his resolve to kill her.

(Source: Anime News Network)