The Twibug

The Twibug is a series of distorted areas found beneath and within Hyrule Field.

It features weird puzzles and Metroid bugs that provide random names of various rescources within the game's code along with instructions on how to use the cheat code system within the game.

There are six entrances to the twibug in total:

Main Twibug
This area is the bulk of the Twibug. It is a massive shadowy dome covering almost all of Hyrule Field. Three different versions of it can be accessed by walking into it, by using a door found deep within the afforementioned region, and by flying into it via the arwing.

The dome of the Twibug shrinks as the game progresses. Each one of the backups collected causes it to shrink. Upon aquisition of the Ghost Medallion, the Twibug will shrink to a permanent size equivalent to X backups remaining out of 100.