All-Night Mask

In Majora's Mask, the All-Night Mask allows the wearer to never fall asleep. In fact, it is impossible to fall asleep while Link is wearing it.

Majora's Mask
While Link needs an entire three day cycle to obtain the mask, it has only one use in the game. If Link wears the mask while listening to the stories of Anju's Grandmother, then he will not fall asleep. At the end of each story, Anju's Grandmother will ask him a simple question, and if Link gives the appropriate answer, he will receive a Piece of Heart.

Obtaining The Mask
Sakon must be stopped from stealing the Big Bomb Bags on the first night, so Link must help out the Old Lady in North Clock Town when Sakon attempts to take the bomb bag. If this is done, then he can't sell them to the Curiosity Shop, and the shop will then sell the All-Night Mask instead. It can be purchased for 500 Rupees on the night of the Final Day.

The Wind Waker
The All-Night Mask appears alongside several other masks behind the counter of the Nintendo Gallery. It can be seen hanging on the wall behind Carlov.