In ancient times, Rauru built the Temple of Time. Afterwards, he remained within the Temple of Light, only leaving the Sacred Realm as Kaepora Gaebora, his owl form. According to a Gossip Stone, he is rumored to be the reincarnation of an ancient Sage.
After Link defeats Gohma and leaves the Kokiri Forest, Kaepora Gaebora is found for the first time in the edge of the woods in Hyrule Field, where it directs Link to Hyrule Castle. Afterwards, it constantly appears before Link in various areas. Kaepora Gaebora can transport Link to various locations, including a secret entrance to a house in Kakariko Village where a Piece of Heart is located.
Ikran's Lost OoT/Pokémon crossover[]
Kaebora Gaebora was first seen on a tall tree as soon as Link, Navi, and Zelda II left the forest and embarked onto Hyrule Field. He advised them time changes quickly, and they should stop by certain locations to slow it down. And at night it's dangerous with all the monsters around. He wished them luck as he told them to follow the signs to Hyrule Castle and see the Princess of Destiny.
He was seen again at the summit of Death Mountain, after Link received a spell from one of the Great Fairies, offering the heroes a ride back down to the village. He was seen once more before Zora's River as they needed to reach their Domain and prove they're the Royal Family's messengers.
At the end of the Spirit Temple, he advised Link to deflect the elemental magic back onto the witches, Koume and Kotake, just before Nabooru was captured. Nevertheless, he still does watch over the heroes, even as the Sage, Rauru. Sometimes to Zelda II, he reminds her of a giant Noctowl.
Unfortunately, he hadn't been seen much since before Ganondorf was sealed away, or during the Imprisonment War as Rauru died then.