The Life & Adventures of Santa Claus 1985

https://www.imdb.com/title/tt0089488/
Directors: Jules Bass / Arthur Rankin Jr.
Writers: Jules Bass / L. Frank Baum

The Great Ak calls a council of the Immortals to ask that Santa Claus be given immortality. To justify it, he tells the story of Santa Claus. The Ak found an abandoned baby and gave it to a lioness and a fairy to raise, who named him Claus. When Claus grew up, the Great Ak showed him the evil and hardship in the world, so Claus decides to live there and relieve some of the suffering. He decides to make toys for orphans, but King Agua, the ruler of the valley where Claus lives, doesn't want the children to be happy, resulting in a great battle with the Immortals.