The catfish in the Swamp of Ill Omen that gives Link the earthquake medallion is based on 18th century Japanese folklore. Namazu is a catfish that would wiggle its body in the water and bring chaos and destruction to the land. The skull shaped stones found on the screen to throw in the circle of stones represents the stone used by Kashima to pin Namazu down and the circle of stones around Namazu represents Namazu's prison (since stones do not float, what the player sees is the top of stones that go to the lake's bottom).