Demon

Demons are a race of monstrous beings that are usually of evil alignment. Although demons are inherently evil and they exude a dark aura that attracts monsters and radically changes the behavior of Animals, very few exceptions exist. They desire to have control over the world and thus constitute a significant threat to Hyrule and its people. Ganon was once known known as the master of demons as the Prince of Darkness. Though out history, those who the spirit of the hero embodies and their Princess Zelda fight and destroy these creatures in order to save Hyrule or other lands.
The terms "demon" and "monster" are sometimes used interchangeably, but generally demons are born from the source of evil while monsters are creatures corrupted by dark magic. Demons command and create evil, while monsters do their bidding.