Blind the Thief

Blind (ブラインド) is the boss of Thieves' Town in A Link to the Past who despises light. He could change his appearance, and took the form of the fourth Maiden that he guarded. However, after he was led under a patch of light by Link, his true form is revealed.

His true form consists of what appears to be a demon covered in flame-red scales, wearing a tattered white robe. To defeat Blind, Link has to slash at him repeatedly until his body collapses. His head continues to fly around the room, spitting fireballs at Link. Eventually, the body reconstructs and grows a new head. Each time Blind's body is reconstructed, the flying head will remain. This in turn makes the battle grow a bit more difficult for the hero, as he will have to strive to dodge these heads. After Blind's body collapses for the third and final time, the true maiden is freed and Link receives a Heart Container.

In the Game Boy Advance version, Blind returns in the Palace of the Four Sword. He first appeared in the form of a wounded Link's Uncle saying "You must rescue the Princess Zelda... You are... the princess's... ... ... ...", before revealing his true form.

Blind's Origins
There is a character within a house in Kakariko Village who references the building to being Blind's former hideout, showing that at one point, he lived in the Light World. Given that Ganon himself is described as having been a thief, and Blind guards one of his captive Maidens, it is possible that Blind is a former friend or minion of the villain. It is also theorized by others that this character is Blind himself, but this just mere speculation, as no proof is ever given to support this claim.