Navi

Navi is Link's trusty psychic fairy from The Legend of Zelda: Ocarina of Time. She is summoned by The Great Deku Tree to accompany Link on his quest to save Hyrule. The only time she speaks during the game (with the exception of the "Hey" and "Listen" sound effects) is during the introductory sequence and during the Temple of Time sequence. At the end of the game, when Link returns to his original time, she leaves him and flies away for unknown reasons.

The most prevalent theory regarding the "friend with whom he parted ways when he finally fulfilled his heroic destiny" (mentioned in the introductory sequence to The Legend of Zelda: Majora's Mask) is that the "friend" is Navi. This is made all the more probable given the 'fairy flying' sound-effect that is played after the text disappears off the screen, but before the Lost Woods scene begins.

Ocarina of Time
She helps Link throughout his adventure by providing information regarding the weaknesses of enemies and bosses, and hints as to what area of Hyrule Link should travel to next in order to further his quest. This system of help is widely criticized amongst fans, many of whom view Navi's input as obnoxious and annoying. Although, some do not see why these fans find her annoying. Navi is a smart fairy, who knew every enemy Link went up against.

Navi forms the in-game mechanism of Link's Z-targetting system.