The Mad Moon is an enemy that only appears in World 2-4: The Moon HATES You. It doesn't move or attack the player until the player moves on for a short time. During the day, the Mad Moon is replaced with the Angry Sun.
- The Mad Moon behaves the same way as the Angry Sun in Super Mario Bros. 3.
- The Mad Moon's appearance close resembles to the Moon from The Legend of Zelda: Majora's Mask.