Levias

Levias is a wise, whale-like Sky Spirit that lives in Thunderhead in Skyward Sword. Despite his appearance as a whiskered whale, Levias is properly referred to as a dragon. Since ancient times, Levias watched over the skies and is knowledgeable in many things, including a section of the Song of the Hero. Levias was corrupted by evil forces and is plagued with parasitic eye-like appendages, possessing him and causing him to attack anyone who came near. Levias has a particular fondness for Pumm's pumpkin soup, which Pumm always offered on a sky isle that had a perpetual rainbow above it, before the Thunderhead engulfed it. Link used this knowledge to his advantage to lure the sky dragon out of the cloud sea and with his crimson loftwing removed the parasites. Upon the removal of the last visible parasite, a Bilocyte occupying Levias' blowhole emerged. Link removed this parasite as well, and upon hearing that Link was searching for the Triforce, Levias informed him of the Song of the Hero, and that Link would need to learn three sections from elemental dragons down on the surface, which Link did. Levias then taught him the final part.

Etymology
Levias's name is derived from Leviathan, a mythological monster from Biblical text. Fittingly, in modern Hebrew, "Leviathan" means "whale".