“Whenever the clock strikes midnight on unlucky nights, the sky turns blood red. That's the blood moon. When that happens, monsters come back to life, no matter how many times you've defeated them. It's happened for so long now that no one really pays it any mind, but I have no plans to give up on my research.”
The Blood Moon only appears on certain nights, between 10pm and midnight, causing Ganon to reach maximum power, and also revives any enemies that were previously killed. It causes a full moon to appear, regardless of the lunar phase; it also causes the moon to turn an ominous red color. Around 11:30, Malice starts to form in the air, and an eerie tune starts playing; between 11:50 and 12 midnight, dark red clouds start to appear, as the music becomes more foreboding. The first time it happens, Princess Zelda explains that the Blood Moon is where Ganon's power is at its peak and brings back any monsters that were slain. In subsequent appearances, the princess notifies him again and tells him to be careful