Lanayru (Dragon)

Lanayru is one of the three elemental Dragons who protect the Surface, and appears in Skyward Sword. He was assigned to protect Lanayru Province by the Goddess, Hylia, and he has power over thunder.

Biography
When Link visits the Lanayru Gorge where the Thunder Dragon is said to rest, all he finds are his skeletal remains. To revive him, Link has to transport a Timeshift Stone through the Lanayru Gorge where an old mining facility remains in ruins. Once Link transports the Timeshift Stone Cart to the power pedestal that uses the Timeshift Stone as a power source, the power pedestal will amplify the Timeshift Stone's effect radius, restoring the area around it to its once lush landscape. Upon reviving Lanayru, Link discovers that he is deathly ill and cannot teach Link the "Song of the Hero". He tells Link that the Ancient Robots were worried about him, so they planted a seedling from the Tree of Life in the Gorge. However, the seedling will not grow anywhere in Lanayru Province, and thus cannot grow the Life Tree Fruit that is said to cure all illnesses.

After relocating the seedling to the Temple of Hylia and allowing the fruit to grow in the Sealed Temple in the present, Link returns to Lanayru Gorge to heal Lanayru. He grasps the huge Life Tree Fruit by the stem and tosses it into Lanayru's gaping mouth. After the Thunder Dragon teaches Link his part of the "Song of the Hero", he tells the young hero to come back soon. If Link does, Lanayru will let Link participate in his Lightning Round mini-game, where Link may re-fight all the previous bosses, excluding Levias and Bilocyte, or explore the Silent Realms once again, for prizes. However, Link is not allowed to use any Adventure Pouch items other than his equipped Shield. Most of the prizes are Rupees or Treasures that can be obtained elsewhere, but there are also two unique prizes: a Piece of Heart after the fourth round and the indestructible Hylian Shield after the eighth round.

Theory
It is possible that Lanayru is the creator of the Ancient Robots. Some of them work directly under him, calling him their master and they seem to care about his well-being.

Trivia

 * Lanayru claims that his life will end before the Life Tree Seedling can grow, and is initially encountered as a skeleton with glowing eyes. However, after he is cured, he claims to have eternal life, indicating that he may have been undead when Link first found him. It is also possible that he lied about his immortality, or that he cannot die of age-related causes but can die by other means.
 * Even after being healed, Lanayru only appears in the past and disappears completely in the present, except when all three dragons, along with Levias, show up in the Thunderhead to teach Link the full "Song of the Hero".
 * Lanayru considers giving Link a model number, "LD-Link-16", but Link isn't fond of the name. The number 16 is likely a reference of the number of canon The Legend of Zelda titles released at the time.