The Wind Fish is a Deity said to have control over the wind in the Zelda series. It is the main focus of The Legend of Zelda: Link's Awakening and its remake as it is the creator of Koholint Island, a world located in the dreams of the Wind Fish and tied to Link's awakening from his otherwise eternal slumber.
The Legend of Zelda series
The Legend of Zelda: Link's Awakening
The Wind Fish fell asleep before the events of the game and started dreaming of another reality that manifested as reality into the Deity's dream as Koholint Island. The inhabitants of the island and the island itself were tied to the dream itself and the eventual awakening of the Wind Fish would bring the end of their existence.
An entity known as the Shadowy Nightmares eventually manifested in the dream and trapped the Wind Fish into an endless slumber, preventing him from ever waking up and preserving the existence of the island as a result. When Link was caught in a storm created unconsciously and struck by lightning, he was transported to Koholint Island. Link started to learn the true nature of the island trought the Owl who is in reality a part of the Wind Fish's spirit trying to influence the hero to bring his eternal slumber to an end. Most inhabitants of the island are unaware of their true nature and the only one who knows realised that Link would destroy the island if he manage to collect the Instruments of the Sirens. Dedicated to protect them, they serves as the bosses of each dungeons.
Eventually Link learns that the island would cease to exist if the Wind Fish would ever be awoken but determined to himself be free from the dream, he collects all the instruments and face the Shadowy Nightmares. After the Nightmares' defeat, Link plays the the "Ballad of the Wind Fish" with the instuments awakening the Deity who explain to Link that eventually all dreams must end. Link awakens on a piece of his wrecked ship while contemplating if it was only a dream, he looks up to see the Wind Fish flying off into the distance with a flock of seagulls.
Hyrule Warriors series
Legends and Definitive Edition
In Hyrule Warriors Legends and Hyrule Warriors: Definitive Edition, the Wind Fish is once again featured as part of Marin's level but is also at the center of the Koholint Island Map, which recreates the story of Link's Awakening.