Forest Spirit

Forest Spirit, also called Shishigami (シシガミ) and Night-Walker (デイダラボッチ, Deidarabotchi), is a supporting character in Princess Mononoke. He is known as a god of life and death.

Appearance
The Forest Spirit looks like a deer, but with more antlers and a human-like face; He can transform into a gigantic, semi-translucent humanoid during the night called the Night-Walker.

Story
The Deer God "Forest Spirit" is the protector of the Cedar Forest and is the God of life and death. He heals Ashitaka of his bullet wound, yet interestingly leaves his curse. Later, he takes the life of Okkoto and Moro. Lady Eboshi shot him as he was transforming into the humanoid-like Night-Walker which then releases his destructive body and steals the life of everything he touches, until Ashitaka and San return his head, restoring peace.

Abilities
The Forest Spirit is immortal and invulnerable. The emperor Mikado believes it's possible to become immortal by eating his head. As Eboshi shows that the Night-Walker is vulnerable by shooting off his head.

The Forest Spirit is a god of life. His blood cures all illness and curses, which can be seen at the end of the movie. When he touches the ground, the plants under his feet die and grow instantly. He can heal wounds by touching them with his mouth, but he can't take away curses by that way.

The Forest Spirit is a god of death. He can end life. Demons don't fear anybody, beside the Forest Spirit. So he takes Okkoto's life, who becomes a demon. Kohroku believes he is gonna die, if he looks into Forest Spirit's eyes. That thinking is just superstition. The Forest Spirit is the Night-Walker. At the Sea of the Forest Spirit, he transforms into the Night-Walker at midnight. If he loses his head, he becomes the Night-Walker with tentacles searching for his head. The tentacles eat everything in their way.

Mythology
In Japanese mythology, he is called Yatsukamizuomitsuno, who is worshipped in. His origin is from script The Kasuga Deer Mandala, where he is seen as a deer with a tree on his head. He is the power that forms a planet.

The Night-Walker is called in Japanese. In the movie, the deer-like Forest Spirit and the Night-Walker are the personification of the Forest. They are neither good nor evil.