Graveyard Boy

The that loiters around Kakariko's graveyard in Ocarina of Time.

The young boy is Dampé's admiring fan. Link can sell him the Spooky Mask he obtains in the Happy Mask Shop; the boy will pay the exact amount needed for the mask.

The boy previously asked his father, the guard at the gate to the Death Mountain Trail, to get him a Keaton Mask. His mother is never seen, but Link can talk to her through the door of their home in Kakariko Village. During the day, she tells Link that her son is off in the graveyard playing, and at night she tells him that her child has gone to bed and that he should come back tomorrow.

Seven years later, when the castle town is destroyed, the boy and his family aren't found anywhere, and their house has been turned into the Bazaar.

Theory
Seeing as the boy is nowhere to be found in the future, a theory is that the little boy could have grown up to become the Poe Collector. The boy seems to have an affinity for scary things,  and both he and the Poe collector carry a stick. A counter-argument to this idea says that the boy is even younger than young Link, and yet the Poe collector seems to be an old man a mere seven years in the future; while the Poe collector never shows his face, and it is therefore impossible to tell exactly how old he is, the fact that he refers to Link as "young man"  would seem to indicate that he is quite a bit older than adult Link. Furthermore, the little boy seems displeased with having a cute face and wishes he looked scarier, whereas the Poe collector admits that he is not handsome and says he might be able to run a different business if he had better looks. The little boy also doesn't seem to like trouble when Link attempts to move gravestones during the day, which contrasts harshly with the Poe collector's desire to see the world fall into disorder, but considering that seven years have passed, it's easily possible for the boy to have changed his attitude.

Trivia

 * The Bombers from Majora's Mask greatly resemble the young boy, and are likely his Terminan counterparts.