Volvagia

Subterranean Lava Dragon: Volvagia (灼熱穴居竜ヴァルバジア Shakunetsu Kekkyoryū Varubajia?, Scorching Hot Cave Dwelling Dragon: Volvagia) is the boss of the Fire Temple, the second dungeon in the adult portion of The Legend of Zelda: Ocarina of Time, and the fifth dungeon overall. Volvagia is a monstrous dragon and was a blight upon Hyrule, specifically Death Mountain, for many years prior to the events of the game. He flies through the air in a blaze of fire and dives through pools of molten lava, unharmed despite their intense heat. Volvagia is infamous among the Gorons for devouring their kind alive, but was eventually defeated and slain by the Hero of the Gorons, who wielded the Megaton Hammer.

Volvagia has existed since ancient times. He was known for his appetite for Gorons and he spread fear and consternation throughout the tribe. Although Volvagia consumed a good portion of the race, he was finally bested by the Hero of the Gorons who defeated him with the assistance of the legendary hammer from the Fire Temple. Although little about the hero was known (save that he was an ancestor of Darunia), his legacy, as well as Volvagia’s, would continue for generations to come.

After an untold number of years, Volvagia is revived by Ganondorf. The ring of clouds surrounding Death Mountain catch fire, reflecting the impending danger. Following this sequence of events, Ganondorf's forces invade Goron City and capture all of the Gorons except for Darunia, his son, Medigoron, Biggoron and the Goron Shop Owner. The captured Gorons are imprisoned inside the Fire Temple for Volvagia to feed on. Ganondorf executes the deed to exemplify the fate of the races who opposed his despotic rule.

Fortunately, Link receives word of Ganondorf's scheme before it could be accomplished. At once, Link heads for the Fire Temple where he meets Darunia directly outside the door to Volvagia's lair. The Goron chieftain tells Link that it is his intent to seal Volvagia inside before it manages to escape, despite not being the holder of the legendary hammer. He beseeches Link to free the other Gorons while he fought with Volvagia. Subsequently, Link ventures through the entire temple, liberates the imprisoned Gorons, and obtains the Megaton Hammer along the way. He then returns to the room he had last seen Darunia and uses the Boss Key to open the door to Volvagia's pit. Once inside, he finds no sign of Darunia. Suddenly, the path behind him melts, and Volvagia emerges from the volcanic magma.

The Hyrule Historia states that Volvagia is thought to be the ancestor of the guardian spirit Valoo from The Legend of Zelda: The Wind Waker, despite Volvagia's evil nature and death at the hands of Link. However, the book does not state this as fact but rather states that it is a possibility.