Ura Zelda

Ura Zelda, later renamed to Legend of Zelda: Master Quest, was an expansion to Legend of Zelda: Ocarina of Time meant to be released on the Nintendo 64DD. It was said to contain rearranged dungeons and other small changes, but was actually planned to contain unused content from the original Ocarina of Time that they couldn't add to the original game. However, when it was completed, the developers couldn't figure out how to release it, and it later was released on the GameCube. However, several people claim to have found the original version of Ura Zelda that is vastly different from the released version.

Master Quest
Upon being released, Ocarina of Time: Master Quest had dungeons rearranged and altered to be more difficult and change progression. Enemies have been moved, new and harder enemies have been added, Gold Skulltulas have been moved, and previously optional items are now required. It was also built-in to Legend of Zelda: Ocarina of Time 3D, with the game being unlocked after clearing the main version of Ocarina of Time. The entire game is mirrored, similarly to Legend of Zelda: Twilight Princess, and all enemies and bosses do twice as much damage to the player. In the original release, several trailers for other games was also included.

Original Ura Zelda
These supposed "lost builds" of Ura Zelda reportedly contain several rumored and removed areas and concepts seen in the original version of Legend of Zelda: Ocarina of Time. This most commonly includes the Unicorn Fountain, Sky Temple, extra tunics, Sword Beam, and the Triforce, but many other things have been reported in these builds. Due to the nature of these claims, they are hard to verify, meaning that what really was meant to be included in Ura Zelda is rather hard to pinpoint. However, it is agreed upon by all reporters that these additions were planned to be in the original Ocarina of Time.

However, it is known that Ura Zelda would have had some removed content from the original Legend of Zelda: Ocarina of Time. Ocarina of Time was originally being developed for the Nintendo 64DD, but was later moved to the main Nintendo 64, causing content to be removed to accompany for cartridges having less space than the discs. Why it was removed in the release of Master Quest is unknown, though it is believed that they may have simply changed their mind on Ura Zelda for one reason or another, potentially due to the failure of the Nintendo 64DD ruining their chances of making it a proper add-on to the original game.

Ocarina of Time Manifestation
Due to Ura Zelda's assets originally being planned for the original Ocarina of Time, if crossing over occurs, the A.I. can dig up unused locations or items that were planned to appear in Ura Zelda. This is technically coincidental, but has resulted in several people finding personalized copies of Ocarina of Time believing them to be a Ura Zelda build. These personalized copies also make it hard to distinguish between an unlabeled build of Ura Zelda and just a personalized copy of Ocarina of Time, making Ura Zelda even more enigmatic.