Volvagia

A legendary monster in Goron lore, Volvagia is the boss residing in the Fire Temple. The fierce, snake like dragon can only be killed with the legendary Megaton Hammer.

Strategy
This dragon is no push over. On the battle field, there are pits of fire that Volvagia comes out from. His head will pop out from one of the pits. Look for one pit that is spitting fire and that is the one most likely he would come out from. Once Volvagia comes out he would do one of two attacks. If you are far away, he will breath fire. If you are up close to him, he will try to slash you. You must get close to him and smack the Megaton Hammer on Volvagia's head. Once stunned, you can slash him or bunk him on the head again. Eventually, he would leave his pit and attack you out on the field. He would either throw rocks at you (watch the shadows of the falling rocks to avoid them), or he will follow you and try to burn you. You can use your arrows at that point to fend Volvagia off. After four smacks with the Megaton Hammer and four slashes with the Master Sword, the almighty dragon is defeated and the Gorons saved.

Trivia
Some specualtion surrounding the beast is that it has some kind of relation to the Valoo, the guardian of the Rito. This is due to the coloring of the two creatures, and that they both, presumably, reside at the same location. (Dragon Roost Island, where Valoo lives, and Death Mountain, where Volvagia lives, are considered to be the same thing.)

In the OoT manga, Volvagia was Link's pet, but Ganon cursed it like Great Deku Tree and Gohma.

Background
Volvagia was an ancient dragon that lived in the depths of the fiery Death Mountain. Long before Link was born it was said that a legendary Goron destroyed Volvagia with the use of the Megaton Hammer. When The Legend of Zelda: Ocarina of Time's story occured, it was then that Ganondorf revived the devastating ferocious being to stop Link in his tracks and kill him.