From Zelda Wiki, the Zelda encyclopedia
The Giant Fish is an enemy featured in the "Fairies in the Spring" episode of the Zelda animated series.
When Link and Princess Zelda go back to the Royal Water Park to look for the princess's kidnapped father, they find a grate that they can go through in one of the park's pools. However, a giant fish suddenly attacks them and grabs the Triforce of Wisdom that Zelda was holding on to. The fish, with Zelda still grabbing onto the Triforce, then swims in through the opening left by the grate as Link pursues it. The young hero, not being able to catch up with the fish and Zelda, asks the princess if she can slow it down. Zelda uses the Triforce's magic to shoot out a beam in front of her which makes a wall of ice that the fish bumps into. This gives time Link to catch up to them, who easily zaps the creature away.