The Legend of Zelda: Ocarina of Time Easter eggs

Steal The Hat At The Fisihing Pond
As an adult when you enter the fishing area, get the rod and cast it at the owner. It might take a few times to get it but it will hook the hat off his head. Then you can either give it back or cast it into the water so it falls off.

He will charge you 50 rupees for a new one but will never get it so he is bald for the rest of the game.