In which game does Link obtain the Fierce Deity's Mask?

In which game does Link obtain the Fierce Deity's Mask? Majora's Mask. Link obtains the Fierce Deity's Mask near the end of The Legend of Zelda: Majora's Mask, inside the Moon. To receive it, he must collect the game's other masks and give the twenty non-transformation masks to the four Moon Children during their hide-and-seek trials.

The final Moon Child, who wears Majora's Mask, gives Link the Fierce Deity's Mask after the other masks have been surrendered. Wearing it transforms Link into Fierce Deity Link, a powerful adult-like form equipped with the Fierce Deity Sword. The sword has a long reach and can fire energy beams when Link has enough magic power.

The mask is especially notable because it can normally be used only in boss rooms. It makes the final battle against Majora dramatically easier, although defeating the game without it is possible. A common mix-up is confusing it with the Deku, Goron, or Zora Masks, which Link obtains earlier and uses to transform throughout Termina. Majora's Mask is also the title of the game and the evil mask worn by the Skull Kid.