Biggoron

Biggoron is an exceptionally large member of the Gorons, and has made several appearances in several games in The Legend of Zelda series.

Ocarina of Time
Biggoron is a gigantic Goron who lives on top of Death Mountain in Ocarina of Time, and is a skilled blade maker. In fact, he made the most powerful weapon in the entire game: the Biggoron Sword. However, Link must go through a lengthy trading sequence in order to obtain this deadly blade. Biggoron has a little brother, Medigoron, who is also into the sword making business, although the quality of his blades is inferior compared to his older brother.

Majora's Mask
Biggoron makes a cameo appearance in Majora's Mask. He is normally invisible and sits at the entrance to the Snowhead Temple, blowing gusts of wind to prevent anyone from entering. However, he is vulnerable to the soothing Goron Lullaby, and upon hearing it, he drifts off to sleep and falls into the gorge below. After defeating Goht and bringing spring to Snowhead, Biggoron can be found standing in the gorge and complaining, apparently unaware of why he was there and what he had been doing.

Oracle of Seasons
Biggoron makes an appearance in Oracle of Seasons, perched atop the peak of Goron Mountain. He is a part the sixth step in the trading sequence; give him Lava Soup to receive the Goron Vase.

By completing Oracle of Seasons, a provided completion password can be used at the beginning of Oracle of Ages. After entering this password and questing partway through the game in Ages, a Goron will provide Link with another password. This password can be told to Biggoron in Seasons in exchange for the Biggoron Sword, a sword so massive and powerful it requires the player to assign it to both A and B buttons (normal items only occupy a single button).

You can also earn the Biggoron Sword in Ages with a password Biggoron provides in a password-linked game of Seasons.

The Minish Cap
In The Minish Cap, Biggoron can nibble on your shield and make it a Mirror Shield.

Quote from The Minish Cap Biggoron figurine:

"This is a legendary Goron with a body bigger than a mountain. It is so big, in fact, that no one has ever seen it all at once."

Phantom Hourglass
In Phantom Hourglass, Biggoron was the name of the chief of Goron Island. Unlike past appearances, Biggoron is the size of an average Goron instead of being a giant. He is the father of Gongoron, and he is also the one that gives Link permission to enter Goron Temple (after having tested him with a quiz.)

Trivia

 * Wearing the Goron Mask while speaking to King Zora reveals that Biggoron and King Zora are best friends, and have known each other since childhood.
 * The name "Biggoron" is a portmanteau of the words "big" and "Goron", referring to his large size.