Link's Uncle

A former knight in service to the royal family of Hyrule, Link's Uncle has been Link's guardian for some time, and taught him how to effectively use a sword in the game A Link to the Past. He could briefly be seen in the Japanese commercial for the game.

At the end of the game after Ganon had been defeated, Link's Uncle is shown to be alive and well in the credits as he recovers in Link's house.

In the Palace of the Four Sword, Link's Uncle appears, wounded. However, when Link speaks with him, he transforms into Blind the Thief.

Trivia

 * Early in the game, Link's uncle says "Zelda is your..." before falling unconscious. This caused some people to speculate that the full sentence would have read "Zelda is your sister", possibly in relation to the film Star Wars Episode VI: Return of the Jedi (less popular sentence endings included "ally" and "only hope"). The Japanese version of the game contains what is essentially the same line ("お、お前は、姫の…　…. ", literally, 'y- you are the Princess's...'). The later Game Boy Advance version omits this line, but it is present on the Virtual Console release.
 * Link's Uncle shares some of his physical traits to Tarin from Link's Awakening, especially how Link's Uncle is depicted on official artworks.
 * Link's Uncle also shares similarities with Rusl from Twilight Princess. They are both swordsmen who serve as Link's mentors, both were wounded during the game, they have the same in-game hairstyle, and they both have facial hair which is a different color than their hair.

Quotes
When he is summoned to the aid of Princess Zelda, he takes off for the castle:

"Link, I'm going out for a bit, but there's no need for you to worry. I'll be back by morning, but I don't want you leaving the house until then... Go back to bed..."

- Link's Uncle

After Link leaves the house, he discovers his uncle wounded in the castle:

"Unnh... That voice... Link? Is it you? I thought I told you to wait at home... I suppose there's no escaping destiny... You must rescue Princess Zelda. Our people are fated to do so."

- Link's Uncle