A race of snake-haired women, who turn any who look at them into stone. They have long ago taken control of the desert west of Llewdor, earning it the name Medusa Desert. They patrol the desert, turning all intruders into grotesque statues. Some of the less moral members of the Port Bruce population have taken to selling the statues of Medusa-victims to foreign countries. The Medusas were led by the Medusa until Gwydion turned her to stone with a mirror.
The Medusas do not appear in any of the King's Quest series, except for the one that appears in King's Quest III: To Heir is Human. There are several implications from several sources that there are more Medusas.