Ocarina of Time

The Ocarina of Time is an important item central to the plots of both Ocarina of Time and Majora's Mask and is the instrument the Hero of Time used to play music. It is set to return in Super Mario Bros. X: Sea Side Adventure.

Background
Long ago in the land of Hyrule, the Ocarina of Time was a sacred instrument given to the Hero of Time. In an alternate timeline where the Hero of Time was also an adult, the Ocarina of Time was found by the Frog King, Wart, after the hero died. Wart hoped that he could perform the Song of Time with it to have the Goddess of Time help him retrieve his other selves from other timelines, which is up for the successful Hero of Time to protect from Ganon.

Hundreds of years had passed in the Downfall Timeline after the Hero of Time was defeated. Wart wasn't able to use the Ocarina of Time yet and he was somehow found in Koholint Island while subconscious somewhere in the outside world, where he was somehow turned into a toad. He then lead the Frog Choir and made his first unreleased cut known as the "Frog's Song of Soul", hoping to be reawaken so he could finally try to use the Ocarina of Time again. He met the hero Link and taught him that song. He realized he somehow looked like the Hero of Time and believed he would make a great hero. Before the Wind Fish woke up, he retrieved some members of the 8-Bits and the Koopa Troop and successfully performs the Frog's Song of Soul with the Ocarina of Time and wake up in the outside world, returning into his original form.

Directly after that, he performed the Song of Time and the Goddess of Time finally reacted and made him traveled trough timelines along with his allies to retrieve his other two selves from other timelines; one who was found somewhere in the darkness (the Child Timeline) and one within the ocean (the Adult Timeline), then fused together as one Frog King and became more exceedingly powerful. He then returned back to his original time from Mushroom World as Hyrule's time is actually more faster than Mushroom World itself, which took place 15 years before the events of Super Mario Bros. X: Sea Side Adventure, and he still has the Ocarina of Time with him.

Trivia

 * Retriving the Ocarina of Time is one of the heroes important quests in Super Mario Bros. X: Sea Side Adventure, similar to that of Majora's Mask.