Volvagia

Volvagia, known by the name Barba in the original release of The Adventure of Link, is a snake-like dragon that has been featured as a dungeon boss twice in the series.

The Adventure of Link
Volvagia, known as Barba in the original release, is the guardian of Three Eye Rock Palace, where Link places one of the six Magic Crystal shards in the palace's lectern in order to rouse Princess Zelda from her unnatural slumber. It breathes fireballs at Link. However, it can be beaten if Link uses the Jump Spell, or by using the upwards sword thrust, though this method is more risky, as it is easier to fall into the lava.

Ocarina of Time
A legendary, snake-like dragon in Goron lore, Subterranean Lava Dragon: Volvagia''' (灼熱穴居竜ヴァルバジア, ') is the boss residing in the Fire Temple. 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. By the time of Ocarina of Time, Ganondorf had revived the fierce creature to secure the corrupted Fire Temple from intrusion and by feeding the native Gorons to Volvagia, to "make an example" to other people that might revolt against him. Incited by Darunia's son, Link set on to destroy Volvagia or else; if the dragon escaped from the temple, Hyrule would become a burning wasteland. In the game, Volvagia is referred to as "it" with a single instance in which its gender is specified as male.

Strategy
The battle is a lot like the Whac-A-Mole game, as there are nine holes, and Link must whack the dragon when it comes out using a hammer. On the battle field, there are pits of fire that Volvagia bursts out of to attack Link. His head pops out from one of the pits. Link looks for one pit that is spitting fire, which is a telltale sign that this pit is the one he most likely comes out from. However, it's advised to not venture too close to the pit as he swings his fire hair around to cause damage. Once Volvagia comes out of one of the nine pits, he would do one of three attacks: (1) Come out halfway of his pit, (2) Rise out of the pit he comes from and hovers above the stage, chasing after Link, or (3) fly up to the ceiling of the cave. When Volvagia comes out only halfway, he does one of two things, depending where Link is at the moment. If Link is far away, he breathes fire. If Link is up close to him, he tries to slash him. Link must get close to him and strike Volvagia's head with the Megaton Hammer. Once stunned, Link can slash him with the Master Sword or hit him on the head again with the hammer until Volvagia recedes back into his pit. Eventually, he leaves his pit and attacks Link out on the field, flying through the air. As said before, he can either cause rocks to fall down at Link (who must watch the shadows of the falling rocks to avoid them), or he will follow him and try to burn him. Link can use his arrows at that point to fend Volvagia off or he can go to the edge of the battle stage and hang there while the rocks fall down. Link can try to pierce him under the chin with the arrow shots.

After four smacks with the Megaton Hammer and four slashes with the Master Sword, the almighty dragon is defeated and the Gorons are saved. Link witnesses the dragon's body burning into a skeleton and his skull crashing to the ground. It moves its jaw one last time and burns up, rewarding Link with a Heart Container and a very pleased Darunia, who awakens as a sage and grants the young hero the Fire Medallion.

Manga
In the Ocarina of Time manga, Volvagia is a dragon that Link bought as a young child. When he returned 7 years later, Volvagia was corrupted by Ganondorf, requiring Link, begrudgingly, to kill it. Volvagia is also able to talk in the manga, although only the word 'Link'. Before his dying breath, tears drop from Volvagia's eyes and he sadly utters "Li...nk...."

Trivia

 * The original name Barba is a mistranslation of "Barubajia", and was corrected in the re-release of The Adventure of Link.
 * Along with King Dodongo (with whom Volvagia shares its battle music), Volvagia is one of the two normal bosses in Ocarina of Time to have a different battle theme.
 * The second part of Stallord's battle, from Twilight Princess, features a song similar to King Dodongo/Volvagia's theme.