Ashei's Sketch

Ashei's sketch is a piece of paper with a sketch of a giant holding a red fish. It is received by Link from Ashei when he talks to her at the beginning of the path to Snowpeak. After showing it to Prince Ralis, the prince will give you a coral earring to help you catch a Reekfish. Ironically, you never get to see what the sketch even looks like.

Trivia
Even though the picture is never revealed to the player, it is highly plausible that the monster on it is a picture of Yeto, as he has the reason of traveling down from Snowpeak to find food to help his sick wife Yeta.