@gavvet In Ocarina of Time, a Skull Kid can be found in the Lost Woods, in the area directly to the left of the entrance room. Whenever Link approaches, the Skull Kid will disappear from the area. To circumvent this, Link can befriend the Skull Kid by playing "Saria's Song" while standing on top of the stump across from the Skull Kid's position. He will then receive a Piece of Heart as a gift.[3] While Z Targeting, Navi mentions that the Skull Kid seems unhappy to have no face.[4] Some of the Kokiri remember hearing him complaining about his face, as well.[5] Upon first seeing Link wearing the Skull Mask, the Skull Kid comments that he would like it to make him appear a little tougher.[6] Link is then able to sell him the mask as part of the Mask Trading Sequence, but the Skull Kid pays just 10 Rupees when the wholesale price is 20, leaving Link to cover the difference.[7] Another two Skull Kids can be found in the area directly to the right of the entrance, where Link can play a Musical Session with them on his Ocarina to win another Piece of Heart.[8][9]
It is said that non-Kokiri who enter the woods become Stalfos upon getting lost.[10] However, there is speculation about whether or not Kokiri or Hylian children turn into Skull Kids. It is more plausible that the Kokiri turn into Skull Kids, due to the fact that they stay children for their whole lives, but also because Stalfos never appear within the Lost Woods, as well as that there already exist Stalchildren.
If Link encounters a Skull Kid as an adult, he will be attacked with needles shot from the Skull Kid's flute. Navi says that they are attacking because they do not like adults.[2] If Link defeats him, the Skull Kid will collapse and disappear, leaving behind an Orange Rupee.