Epona raced through the grasslands, Link on her back. The wielder of the Master Sword saw a small dead tree, and at the base, something that caught his eye. Urging the horse to slow to a trot, Epona obeyed, and a moment later, came to a halt near the tree.
Link dismounted, and went closer. Almost hidden by the grass at the base of the rotting trunk, was a weathered wooden chest, yet the gold banding on it still shone. A blue feather was carved into the lid.
Picking it up, it seemed clear the small chest was for some jewellery or other valuable, but it was held shut only by a simple looking and badly rusted lock. Link pondered his options. Leave it, take it, or just open it now?
He decided the latter. Forcing it open was simple enough, just some brute force and the corroded iron just crumbled away. Inside was a golden mask lying on a blue velvet lining. It seemed to have an avian design, and three feathers in white stuck out above the eyes. The beak portion seemed to be carved from a dark wood, but the rest of the mask was otherwise gold, with a faintly engraved feather pattern across it.
Link's first thought was not that the item was valuable, but an odd urge to try it on. He held the golden item to his face, and then barely had a moment to cry out in surprise as it glowed. Blinded by the sudden flash, all he felt was a strange pain across his body, little pinpricks across his skin and a sensation like something pulling out, while his bones ached and muscles felt like they stretched. He heard a startled whinny from Epona, and then fell back, blinking. He raised his feathered hands to his beak and....
... Wait.
He scrabbled to his feet, looking down a brown beak at his legs. His boots were gone and avian feet poked out from reshapen leggings, fitting birdlike legs. Yellow feathers covered his arms/wings and his fingers seemed to be feathers too, his tunic sleeves gone. He chirped in surprise and then grabbed his beak in embarrassment.
Then realised with dismay he couldn't feel the mask. Whatever it had done, it too had vanished it seemed. He ran feathers all over his Ritofied head but found no sign of something to pull.
He looked at Epona, the baffled horse looking back as if to say 'I've not a clue what happened either. I'm a horse.'
Link considered his options, and decided that perhaps the Rito might be able to figure out what had happened and how to undo it....