Grass Whistle

are objects in. They are plants that grow in many places in Hyrule. With them, Link can whistle tunes to summon either a hawk or Epona. As Wolf Link, Link can howl the appropriate tune when he is near either type of Grass Whistle.

Hawk Grass
Hawk Grass can be used to summon hawks, which can be aimed and released to retrieve faraway objects or attack enemies.

Horse Grass
Horse Grass can be used to call Epona.