Daisetsusan no Yuusha Kibaou
English name: King Fang
Genres: Adventure, Drama
Type: Special, Episodes: 1
Aired: Sep 23, 1978
Studio: Nippon Animation
Source: Novel
Rating: PG-13 - Teens 13 or older
Synopsis:
The conflicting fates of human beings and wild animals are depicted in a naturalistic setting. The main character of the story is Fang, who was born to a hunting dog and a circus-runaway European wolf. Although Fang was raised by a human family, he is a wild animal after all, and is destined to live amongst nature. The story reaches its climax when Fang returns from the circus and faces his foe, a giant brown bear which killed his family. 

(Source: AnimeNfo)