The Moon (月) is the main threat of The Legend of Zelda: Majora's Mask.
The Moon, controlled by Skull Kid under the effects of the titular mask, is the constant threat of The Legend of Zelda: Majora's Mask. Link is given three in-game days to save the land of Termina from the Moon's destruction (however, he can turn back time with the Ocarina of Time).
In the Super Smash Flash series
In Super Smash Flash 2, the Moon cameos in the background of Clock Town. After minutes pass, the moon will begin to fall towards the stage, before the Song of Time plays in the background, the Moon back in the sky.