Catfish

The Catfish is a character in who has made his home inside the circle of rocks in Lake of Ill Omen, in the Dark World.

Near the ring where the Catfish dwells, there is a sign that says: "Curses to anyone who throws something into my circle of stones." If Link ignores the sign and follows the advice of the bird-like creature in a cave south of the Palace of Darkness by throwing a skull, a bush, or the sign itself into the circle of stones, the great Catfish, who was having a nap, appears and gives him the Quake Medallion in return for leaving it alone.

After that, disturbing it by throwing another item into the ring of stones causes the Catfish to spit a fireball or throw a Bomb out.

Link's Awakening
In Link's Awakening, a location known as the Catfish is home to the Catfish's Maw dungeon. It is a large, motionless statue that acts as an entrance to the dungeon and lies in the center of Martha's Bay. Like the Catfish in A Link to the Past, it sits in a circle of stones. To access it, Link will have to dive through a secret passageway under the rocks.

Trivia

 * The Japanese name of the Catfish is . In Japanese mythology, Namazu is a gigantic catfish who has the power to cause earthquakes.
 * The Ocean Floor entrance above the surface in Spirit Tracks is also shaped like a giant catfish.