Rushroom Rush!

Rushroom Rush! is a Side Quest in.

Overview
At the Gerudo Canyon Stable, there is an old man named Pirou. He tells Link that he feels out of energy without Rushrooms. Pirou offers Link a Diamond if he gives him 55 Rushrooms. After giving him 55 Rushrooms, Pirou tells Link that he left the Diamond for him behind the Stable. Pirou also questions why Link went through all the trouble for a Diamond. Link can come back to Pirou any time to exchange 55 Rushrooms for twice the market value. After the Quest is complete, Link will find a Treasure Chest behind the stable containing the Diamond that Pirou promised to give him.