Hero's Spirit
The Hero's Shade is a character from Twilight Princess who teaches Link the seven Hidden Skills. The Hero's Shade is very skilled with a Sword, and he is missing one eye. He appears to be similar to a Stalfos in appearance.
The Hero's Shade is the spirit of an ancient warrior who once saved the land of Hyrule. He wishes to pass on his skills to Link, a member of his bloodline. He has the ability to turn in to a golden wolf, similar to how Link turns into a wolf in the Twilight. He is first seen in this form outside of the Forest Temple. After their first encounter, Link can meet him by howling at a Howling Stone, where they howl a duet in wolf form. A symbol then appears on Link's map where he can find the golden wolf. When encountering the wolf, the beast initially attacks Lthe young hero, which in turn warps him to a strange, foggy dimension with a faint outline of a castle in the background. The shade then appears in his true form and teaches Link one of the seven Hidden Skills.
In Hyrule Historia, it is revealed that the Hero's Shade is actually the Hero of Time, Link, from Ocarina of Time and Majora's Mask.