The Ilkorts are creatures who burrow beneath the Mystic Mountains, and sworn enemies of the Bird People of Avion.
In Siege of Avion, the Ilkorts attack Avion as a distraction so their ally Skeletor can steal the Emerald Staff of Avion. They also kidnap Delora, but He-Man, Man-At-Arms and Teela help Stratos to rescue her.