Moon Children

The Children of the Moon are characters featured in Majora's Mask.

Overview
The Moon Children are among the most mysterious aspects surrounding the surface of the Moon. There are five Children, four of which are running around the tree in the center of the field while the fifth sits at the bottom of the tree. The four running children each wear one of the masks that are dropped once the boss enemies are defeated while the fifth wears Majora's Mask. The Children are each identical in height, clothing, and hair color, differing only in the mask they wear. Their gender is debatable but their haircut seems to indicate that they are male.

The children's behavior is also odd. The four ask for different amounts of masks from Link. In return, they agree to play Hide and Seek with him and send him into different mini-puzzle dungeons that are thematically similar to the dungeon ruled by the boss who's mask they wear. Each of these teleportations is accompanied with an enigmatic, slightly disturbing question that concerns Link's, and the player's, beliefs about the world around them, after which the children will ask Link for more masks. The children casually refer to the life-threatening dungeons they send Link into as "games". After Link returns from each dungeon, the child leaves Link alone, their purpose completed. However, if Link did not obtain all of the masks in the game, he cannot complete all of the puzzle dungeons and, consequently, cannot get the Fierce Deity's Mask.

The final child, the one wearing Majora's Mask, will send Link into the final boss battle with the Mask itself if asked. His behavior mimics the other Children as he refers to the fight as a game. He does not ask a disturbing question, but he mentions the absence of the other children if Link has completed the four puzzle dungeons. Furthermore, if Link successfully obtained every mask in the game and gave them to the other children, the final one will comment on this and give Link the Fierce Deity's Mask, the most powerful transformation mask in the game.

Moon Children's Questions
The four children begin their strange sayings in the puzzle dungeons with "Heh, heh... Thanks. You're nice. Umm... Can I ask... a question?" before continuing.

"Your friends... What kind of... people are they? I wonder... Do these people... think of you... as a friend?"

- Child wearing Odolwa's mask

"Your true face... What kind of... face is it? I wonder... The face under the mask... Is that... your true face?"

- Child wearing Twinmold's mask

"The right thing...what is it? I wonder...if you do the right thing...does it make...everybody...happy?"

- Child wearing Gyorg's mask

"What makes you happy? I wonder...what makes you happy...does it make...others happy, too?"

- Child wearing Goht's mask

Theories
The children's only appearance is on the Moon. They are not mentioned or seen in any shape or form in the rest of the game or the rest of the series. The only ideas regarding their origins are mentioned in an offhand comment while the Happy Mask Salesman describes Majora's Mask early in the game.

Tribe Members
The Salesman mentions a tribe that once owned Majora's Mask. Some believe the children are the last remnant of that tribe.

War Victims
Others believe Majora once waged war on the tribes represented by the boss enemies and the Fierce Deity. The children could be the spiritual remnants of those tribes, which would explain why the other children won't play with the one wearing Majora's Mask.

Happy Mask Salesmen
The children look eerily similar to the Happy Mask Salesman (haircut, pale skin), and even ask Link if he will also be a Mask Salesman.

Memory of the Giants
One theory proposes that the children are the memories of Skull Kid's friends before they became the Four Giants. After they became gods, Skull Kid used the power of Majora's Mask to imprison them within their own masks and transformed the masks into bosses, and the child wearing Majora's Mask would be his idea of himself now and how the giants wouldn't interact with him.