The Goron Mask is an item that appears in The Legend of Zelda: Ocarina of Time and The Legend of Zelda: Majora's Mask. It is a mask shaped like a Goron's face. It originally plays a very minor role in Ocarina of Time, serving as a reward for completing the Happy Mask side quest. This version possesses no special abilities but will change the dialog of NPCs when spoken to while wearing it.
In Majora's Mask, a different Goron Mask appears with a much larger role, housing the soul of the legendary Goron hero Darmani. When worn it let's Link inhabit Darmani's body and gain the abilities of a Goron.