Deku Mask

The Deku Mask is an item in. It resembles the face of a Deku Scrub.

Location and Uses
The Deku Mask is one of four Transformation Masks, the other three being the Goron Mask, the Zora Mask, and the Fierce Deity's Mask. When worn, it transforms Link into a Deku Scrub. The mask contains the spirit of the Deku Butler's Son that Link inhabits when donning the mask, granting him new abilities. With the transformation comes the special abilities of that species; including a new fighting style, the ability to hop across water, a bubble attack that uses Magic Power, and the ability to briefly fly by using a Deku Flower.

Link is first transformed into a Deku Scrub after he follows Skull Kid into Termina, who curses him into this image. The curse is lifted and the mask is acquired upon learning the "Song of Healing" from the Happy Mask Salesman. In order to achieve this, Link must first retrieve the that was stolen from him by the Skull Kid. The song causes the Deku spirit residing in Link to be encased within a mask, which then falls at his feet. The Happy Mask Salesman then tells Link to keep the mask as a memento. With the mask, Link can freely transform into a Deku Scrub at will.

The Spirit Within the Mask
During his travel through the Catacombs, Link runs across a tree bearing resemblance to a Deku Scrub, which Tatl even points out as looking like Link. During the ending credits, the Deku Butler, who lost his son, is seen standing near the tree. It is possible that he was killed by Skull Kid, who then uses his spirit to transform Link.

Trivia

 * In January 2001, Nintendo Power held a contest where the winners of the second prize would receive a copy of Majora's Mask and one of five ceramic replicas of the masks used in the game. These include the Deku and Zora Masks.