Mido is the absurd and dispectful leader of the Kokiri in Ocarina of Time. He guards the entrance to the path that leads to the Great Deku Tree. Just like the rest of the Kokiri, he resides in Kokiri Forest. He holds a large grudge against Link, teasing him by calling him "Mr. No Fairy". He holds said grudge due to Link's positive relations with Saria, a young Kokiri girl who Mido adores.
In the very beginning of Ocarina of Time, he demands that Link gets a Sword and Shield before visiting the Great Deku Tree. This is because he doesn't believe that "Mr. No-Fairy" can handle what the deity of the forest has to offer. Upon Link's completion of Inside the Deku Tree, Mido blames Link for the tree's untimely demise. When Link is an adult, and both leave, Mido learns the error of his ways and tells Adult Link to forgive Young Link if he sees him. He is completely unaware that Link and the person he wants to forgive are the same person.
Mido's Model from Ocarina of Time