Mask of Scents
When the Deku Princess has been rescued, Link can speak to the Deku Butler and he tells Link to meet him at the Deku Shrine. When Link talks to him there, he wants Link to follow him, similar to Dampé in Ocarina of Time. If Link finishes the course, he receives the Mask of Scents. The Mask of Scents looks like the face of a pig and Link can use it to sniff out Magic Mushrooms (In the toilet of the Stock Pot Inn and in a pair of underwear in one of the rooms in the same house). The Magic Mushrooms may be used at the Magic Hags' Potion Shop to make Blue Potion.