You don't kill Jabu Jabu yourself. However, after seven years pass and you become Adult Link, where Jabu Jabu is in Zora's Fountain is replaced by ice. There's no explanation for his absence, although it's possible that Ganondorf may have killed him.
Inside lord jabu jabu's belly.
Barinade is the boss of Inside Jabu-Jabu's Belly, the third dungeon in The Legend of Zelda: Ocarina of Time. This parasitic organism is revealed to be the cause of Lord Jabu-Jabu's gastrointestinal distress. It appears to have a symbiotic relationship of some sort with Bari.
I am not sure this is what you meant but to get into Jabu-Jabu you take a fish and put it right in front of his mouth
You get the boomerang while you're a child in Lord Jabu-Jabu's stomach. It is obtained after beating the mini-boss.
Use your boomerang and make it around the wall and hit the swicth
She is inside Lord Jabu-Jabu
Go inside the dragon looking fish in zoras cave, it's in Lord Jabu-Jabu stomach when you are young Link. There is a room with tentacles blocking your way almost everywhere. But there is one door you can go and you have to kill all monsters in this room and you'll get the boomerang.
Ja Bu Ja bu is also known as the mighty petar who saves little noor and then a goron named hana who comes and gives them flowers and then you can kill him with the flowers
In Lord Jabu-Jabu stomach there a room with doors blocked electric things that are different colors. Go to the door at the far right and fight the enemies in there. Your reward will be the Boomrang.
CHILD DUNGEONS (1) The Great Deku Tree (2) Dodongo's Cavern (3) Lord Jabu-Jabu's Belly ADULT DUNGEONS (1) Forest Temple (2) Fire Temple (3) Water Temple (4) Shadow Temple (5) Spirit Temple
Ahoy, there! If you mean Bigocto, he is where the Spiritual Stone is being placed. You fight him after Princess Ruto is taken away. To reach here, you need to have cut the tail of the green thing that is in the first room you meet Ruto. All you have to do is jump (with Ruto) in the hole the green thing was blocking.
While the game doesn't show this (you're supposed to be the hero who never gives up, after all), what most likely happens is that she's trapped in Lord Jabu Jabu without a way to get out. She'll never be able to go back to her father, who is worried sick about her, and there's the possibility that she ends up getting killed by Barinade.