Mido
Mido is the moody Kokiri Child that lives in Kokiri Forest in Ocarina of Time. He is the guardian to the passage that leads to the Great Deku Tree's Meadow. He won't let Link past unless he has a sword and a shield. Link and Mido were constant rivals for Saria's friendship and affection. What made Mido even more jealous was the fact that Link got chosen over Mido to see the Great Deku Tree, giving Mido a severe inferiority complex. After destroying the creature from Ganondorf inside the Deku Tree, Link was given the task of saving Hyrule. After this, the Deku Tree died as a result of the curse laid on him by Ganondorf. Mido was quick to blame Link for this but memories of him were soon forgotten when Link left the village and didn't return for seven years. When Link returned to the forest as an adult Mido said he looked like a child he had nearly forgotten. After playing Saria's Song in front of him, Mido knew that Link must be one of Saria's friends (Saria herself had just been captured) and gave Link passage to the Forest Temple. Mido was seen at the end of Link's journey in the celebration in Lon Lon Ranch. He was the only one at the party that seemed to grieve, besides King Zora, whom he was sitting next to, knowing that, as the Sage of Forest, Saria would never be able to physically see him again.
Trivia
In The Adventure of Link, there is also a town called Mido.
The last thing Mido says to Child Link is "Grumble Grumble". In The Legend of Zelda, there is a moblin that is hungry and you have to give him something, and all he says is "Grumble Grumble".
