Bug: If you stand in front of a bug or a fish and press start right after swinging a bottle at it, you can put another item in the bottle's place and turn it into another bottle. When this happens, the erased item cannot be recovered, and the new bottle will retain the limitations of the original item (for example, turning the Claim Check into a bottle will still be unable to be used by Young Link.).
Bug: For both the Nintendo 64 version and the Nintendo 3DS version. Go inside the Thieves' Hideout in Gerudo Valley and look for a pot that is boiling. When you do, stand next to it and Navi will appear and turn green indicating that there is something hidden there. However, playing any song on the ocarina will not make anything appear.
Chosen answer: There is another thing it does for the player. Deep in the Lost Woods is an area with two creatures that will sell the player items. Look for where you see a bunch of butterflies gathered. Head toward them and you will fall into a hole. When you land put on the Mask of Truth and slowly walk forward. Some Deku creatures will pop out and look at you. After this talk to the big Deku creature to the right and he will increase your ability to hold more Deku nuts. Wearing other masks from the Happy Mask shop will also have different reactions from the Deku Scrubs.