Fishman

Fishmen are a fish-like race found in the Great Sea with human-like faces. If Link puts out bait in the Great Sea while fish are near, a Fishman will come and eat the bait. As a reward, they will paint the nearby island on Link's chart and give information about the area as well. In the water, a Fishman is a silhouette of a fish. Some time in the past, King Daphnes Nohansen Hyrule helped them out and this is the reason they are willing to help Link. The Fishmen refer to him only as a boat though indicating that they either only knew him as the King of Red Lions, or they know his true identity but are keeping it secret.

Locations
Fishmen are located near every island in the Great Sea. They can be found all around islands, but most of the time they are only near inhabited parts of the island (where Link is likely to be. For example, the Fishman at Forest Haven is more likely to be near the entrance than swimming around the Forbidden Woods).

Fishmen can be seen jumping in the air and splashing around before Link gets near them. In fact, the best way to spot them is not by the fish itself, but by its splash. Once Link approaches close enough, the Fishman will come swimming up to and around the boat (this is when you can L-Target him). Drop the bait only when the fishman is swimming around the boat or the bait will go to waste.

Minigame
If you possess the Hero's Bow, you can play a special minigame by feeding a fishman you have already fed. After giving you the information once more, the fishman will take notice of your bow and ask if you want to place a game. He will give you some arrows and will jump around in the water. You must fire the arrows and attempt to hit him when he breaks the surface. For every hit you connect, the fishman will give you Rupees. The fishmen claim that living in the Great Sea has made them tough, so they will not be hurt by the arrows. They also claim that they suffer from stiff necks, so some "acupuncture" will do them good. It is interesting to note that when the minigame is done and the fishman gives you your Rupees, he still has arrows stuck in him.