Jabun

In The Wind Waker, Jabun (ジャブー, Jabuu) is a giant fish known as the Water Spirit who used to live at Greatfish Isle. He can only speak Ancient Hylian. Before Greatfish Isle was destroyed, he sensed Ganondorf coming and fled to a cave hidden in Outset Island. Knowing of his whereabouts and seeking the third pearl, the King of Red Lions and Link sailed to his new home. Although Jabun first hesitated to hand over Nayru's Pearl to one who had no connection to the Hero of Time, the Water Spirit ended up giving the final pearl to Link, leaving it up to the gods to test the true courage of the young hero.

It is possible that Jabun is Jabu-Jabu (or a descendant of Jabu-jabu) whose name is now pronounced differently when spoken with the new language. The Japanese for Jabun is pronounced "Jabu" and the music played whilst meeting Jabun is a remix of the theme played Inside Jabu Jabu's Belly. If it is the case that Jabun is Jabu-Jabu, then he would know the whereabouts of the Zora, or at least what happened to them, for he was their guardian deity. Perhaps they once lived at Greatfish Isle under his watch. However, rumor has it that they evolved into the Rito (which possess a similar name to the Zora Sage, Ruto, and if so, then perhaps Jabun (Jabu-Jabu) transformed the Zora into the Rito for survival (and perhaps acceptance) purposes and named them after Ruto. Then of course, through the evolution of the Hylian language, they became the Rito, rather than the Ruto.

This theory can also be further accepted because in the earth temple, when you meet the Zora priestess, she says that only those in her BLOODLINE can take her place, and the Medli, the Rito girl who plays the lyre, ends up taking her place in the temple. Clearly there is some cross-species bloodline that would only make sense if the Zoras were transformed into the Rito. Also, the wings of the Rito look a bit like the fins on the arms of the Zora.