The Legend of Zelda: Ocarina of Time Master Quest/Jabu-Jabu's Belly

Getting to this dungeon requires getting the Silver Scale, the Letter in a Bottle, and a fish fed to Jabu-Jabu.

Finding the Zora Princess
Once you enter the dungeon you will notice many strange things within. First, blast open the boulder with a bomb. There will be a yellow switch beneath it. Pressing the switch will make a chest appear. The chest holds the dungeon map. If you shoot the cow on the left with your slingshot, the membrane over the door will disappear allowing you to continue.

In this room you encounter Biri for the first time. Right now the best way to deal with them is to use bombs. To open the door across from you, drop down the hole to the bottom of the room. Down here you will see a cow in a hole. Shoot it to make a treasure chest appear. The chest is through the little hole. Just dive down into it. Be careful of the Stinger. On the other side you will find a yellow switch and the chest. Inside of the chest is the Compass. Pressing the switch will make the door above open up. Go back through the hole and climb onto the spiked platform to go back up. Jump off towards the door. Be sure not to touch the wiggling red things and get through the door.

Here you find the Zora Princess, Ruto. She will ask you why you are in this giant fish, and claim not to have written the letter in the bottle. After this she tries to walk away, but falls down one of the pits in the room. Drop down after her.

Boomerang
If you talk to her two more times, she will let you carry her through the dungeon. Instead, shoot the cow heads to have them drop chests. One has Deku Nuts in it, the other has Bombchus. Make sure to get the Bombchus – you need them. Step on the yellow switch on the floor to have water raise you up. Jump over to the platform with Ruto and pick her up. Jump down and throw her to the platform with a blue switch on it. Step on the yellow switch again and get on the platform. Pick up Ruto again and step on the switch, then set Ruto down on it. One final time, step on the yellow switch so you can get to the platform with the newly opened door.

In here another Lizalfo comes down and attacks you. After you kill him move deeper into the room. You will see a Like-Like in the water, with two stingers swimming around. Bombs (not bombchus) do wonders in this room. After you get rid of all the enemies, the chest holding the Boomerang will appear. Press the yellow switch in the middle of the water to raise the water level so you can reach the vines to climb up and open the chest.

To Mini-Boss
Getting out of this room can be done in two ways. Both put you in familiar territory. If you go back out the way you came, go up the vines next to where you got the bombchus. If you go out the other way, use the spiked platform to get back up to the room full of pits.

In the corner of the room near the pit that Ruto fell down you will find three boulders on the wall. Send a bombchu up to reveal a cow. Shoot the cow to open the door behind the red wiggling thing in the room. Go over to it and throw your boomerang at it. It will be stunned and you can climb over it to the door.

When in this room, go through the path to the right, past the web covered doorway to the next door. Hit the cows one at a time. They will each drop a Like-Like on you. After defeating both of them you will open the door, light the torch, and make a chest with a Deku Stick appear. Use the stick to light the web in the hall off the doorway, and get into that room.

In this room is a giant tentacle hanging from the ceiling. To kill it you have to throw the boomerang at its center three times. After you hit it once with the boomerang it will retreat up into the ceiling until you get close enough for it to strike you. You have to get close, but be quick and throw the boomerang at it again. Once it is dead, all of the blue colored tentacles will be gone. Next is the red colored tentacle.

Go back to the center of the branching hallways. In the center hallway you will see boulders. They shouldn't concern you right now. Just walk about halfway down the hall to trigger the Lizalfo. After it is dead, blow up the boulders with a bomb to reveal a blue switch, then go to the opposite hallway you did before. You will see small crates lying on the ground. Pick one up and set it on the blue switch to get to the next room. The room contains a tentacle just like the last one. Once it is destroyed, go back down the hallway you came from and kill the Lizalfo again. Now go back to the hallway with the crates, and go through the hallway on the far left. In here is the last tentacle, the green one. Once it is defeated go back to the room with all the pits and go back to Ruto.

Once back, pick her up and step on the yellow switch. When the water gets to the top, jump over to the highest platform you can reach. Go through that door. Ruto will be all excited because she found what she was looking for. Just throw her on the platform and get ready for a fight.

Mini-Boss: Big Octo (Quick Strategies)
If you need more help see Full Big Octo Strategy
 * Throw your boomerang to stun him.
 * After the stun wears off he will spin and either face you or his back to you.
 * If his back is towards you, hit him with your boomerang and you will see his weak spot.
 * If his face is towards you, hit him with your boomerang and hope that he faces the other way.

To Boss
Jump on the platform in the center of the room and it will rise up. Look for the cow head and shoot it. This will open the door. Inside you will see two wiggly red things. First, in the back of the room is a cow head. Shoot it with your slingshot. This will make two small crates appear behind you. Pick one up and set it down closer to the red wiggly thing. You are going to have to carry it over them. Throw the boomerang at the first one and stun it, then jump on top of it with the crate, and set the crate down. Hit the second one, pick up the crate, and jump over the second one to the door with a blue switch in front of it. Set the crate on the blue switch and go through the door.

Go through and jump across the gap. The platform will lower itself and will give you access to a part of the dungeon that was inaccessible. Go through that door. In here look to your right to see a cow head. Shoot it once, and it should drop rupees and rise up. Shoot it two more times and it will open the door to the boss. Just jump down and run towards the door while avoiding the Like-Like below.

Boss: Barinade

 * Avoid electricity shot at you by side-hopping.
 * Destroy three tentacles at top.
 * Wait for Barinade to stop, then destroy all his jellyfish.
 * If needed, repeat this.
 * After the jellyfish are gone, he will spin around the room.
 * Hit him with your boomerang to stop him, and start attacking him.
 * When his body falls beneath the floor, just avoid the electricity being shot at you.