Zora Scale

The Zora Scale is a recurring item in the Legend of Zelda series.

The Legend of Zelda: Oracle of Ages
Link receives the Zora Scale from one of the Zora after he defeats Plasmarine, releasing the Rolling Sea from Jabu-Jabu's belly. Possession of the Zora Scale identifies him as the Zoras' hero, and gives him permission to enter the ring of whirlpools in the Sea of Storms. Once there, he meets the Pirate Captain and gives him the Zora Scale in exchange for the Tokay eyeball.

The Legend of Zelda: Phantom Hourglass
The Zora Scale is a treasure item. Link can sell it to the Treasure Teller on Mercay Island for a random but fixed number of Rupees. It is also considered very valuable by members of the Ho Ho Tribe.