Wind Fish's Egg
The Wind Fish's Egg is the egg that the mystical Wind Fish is asleep inside of on top of Mt. Tamaranch in the Tal Tal Mountain Range. He can only be awoken when Link gathers the Eight Instruments of the Sirens and plays the Ballad of the Wind Fish. After doing so, the egg will open and Link must enter and defeat The Shadow Nightmares. However, in order to navigate through the maze-like area, Link must read Dark Secrets and Mysteries of Koholint Island in the Mabe Village Library, which will tell him the directions to take.