The third and final dungeon during the 'child' period of Ocarina of Time. While searching for the Spiritual Stones at the behest of the Great Deku Tree, Link learns from King Zora that the sacred fish Lord Jabu-Jabu has been acting strangely and swallowed his daughter, Princess Ruto. Link is then forced to go inside the massive fish to get her out by luring it into swallowing him by using a fish as bait.
Once inside the fish, Link finds that Jabu-Jabu has become host for a whole host of aquatic enemies, including Octorocks and electrifying floating jellyfish, which shock him if he attacks them with his sword. He also finds Princess Ruto still alive, and is forced to escort her through several rooms in the dungeon, occasionally using her to help him weigh down switches and solve puzzles. Ruto tells Link that she cannot leave without retrieving the Spiritual Stone of Water, which she lost after being swallowed. Link also finds the Boomerang inside Jabu-Jabu's belly, which allows him to hit far-away switches and attack the jellyfish enemies without being electrocuted. After finding the Boomerang, Link eventually reaches a room where Ruto sees the Spiritual Stone, but she is attacked by a giant Octorock who Link then has to defeat. The giant Octorock is only vulnerable from behind, forcing Link to stun it with his newly acquired Boomerang and then stab it in its weak point before it can recover. Once the giant Octorock is defeated and the Spiritual Stone is retrieved, Link and Ruto begin to search for an exit.
Boss: Barinade (Bio-electric Anemone)
In the center of Jabu-Jabu's belly, Link confronts the massive Barinade, an anemone that has parasitically attached itself to Jabu-Jabu and caused its sickness. Barinade is out of reach of Link's sword at the beginning of the fight, suspended from the top of the chamber by three tubes. While Barinade is attached to the ceiling, it attacks Link primarily by shooting lightning bolts from its tentacles. However, by hitting the tubes with his Boomerang, Link can drop Barinade to the floor, stunning it and opening it to attack. Once Barinade is separated from the ceiling, it summons a cloud of electrified jellyfish like the ones Link encountered throughout Jaby-Jabu's belly to surround and protect its vulnerable body. Barinade now spins throughout the chamber rapidly while firing lightning bolts at Link, who must remove the jellyfish with the boomerang and stun Barinade before attacking the anemone itself. After enough sword strikes, Barinade finally dies, leaving behind a Heart Container and restoring Jabu-Jabu to health.
Link and Ruto reunite outside Jabu-Jabu, where she shows admiration for his exploits against the monsters. As payment, he requests that she give him Zora's Sapphire, the final key Link requires to enter the Temple of Time and retrieve the Master Sword. Ruto agrees, but Link does not realize that the heirloom also serves as a symbol of betrothal for the Zora royalty. When he returns to the realm of the Zora as an adult, he finds an older Ruto who is very unhappy that he has abandoned their engagement for seven years, to his surprise.