Goron Mask

The Goron Mask is a mask featured in Ocarina of Time and more prominently in Majora's Mask.

Ocarina of Time
In Ocarina of Time, the Goron Mask was simply for amusement; it had absolutely no function other than to see people's reactions to it. It can be borrowed from the The Happy Mask Shop after completing the Mask Trading Sidequest.

Majora's Mask
The version of the mask in Majora's Mask was much more powerful, in that it transformed Link into a Goron.

Obtaining the Mask
In Snowhead, you must obtain the Lens of Truth. Once you have it, upon jumping over all of the invisible platforms leading back from the Lens of Truth's holding area, you will see a ghost of a Goron named Darmani. Talk to him, and he will ask you to follow him. Do so. He will lead you to the Goron Graveyard, where his body was buried. He will ask that you help his soul move on. By playing the Song of Healing, you will heal him and his spirit will be encased inside the mask.