Fish

Fish are aquatic creatures that reappear throughout the the Legend of Zelda series. In most games, they can be stored in bottles and can be used to feed animals or to trade in exchange for Rupees.

The Legend of Zelda: A Link to the Past
Fish can be picked up when they are flopping around on the ground. The fish can either be thrown back into a body of water or sold to the bottle merchant in Kakariko Village for Rupees. Furthermore, a fish released into water will reward Link with 20 Rupees.

The Legend of Zelda: Link's Awakening
Link can catch fish while playing the fishing mini-game near Mabe Village. There are two kinds of fish in the fishing pond; small runt-like fish and large, puffer-fish like ones. If Link manages to hook and reel in the bigger fish closest to land, he will obtain a Piece of Heart along with some Rupees.

The Legend of Zelda: Ocarina of Time
Fish can be caught in bottles. They can also be purchased in various stores throughout Hyrule and then stored in a bottle. However, Link can only purchase fish once he has obtained an Adult's Wallet by destroyed 10 Gold Skulltulas.

A fish is required in order to enter Jabu-Jabu's Belly for the first time. Dropping it anywhere on the platform in front of Lord Jabu-Jabu will cause him to open his mouth and suck in both the fish and Link. On subsequent entrances, Jabu-Jabu will simply open his mouth and allow Link to walk in.

The Legend of Zelda: Majora's Mask
Fish in Majora's Mask are obtained in the same way as in Ocarina of Time, by swinging an empty bottle near fish in shallow water. Fish are also sold in various stores throughout Termina.

Two menacing-looking fish can be found in the Marine Research Laboratory, and Link can drop regular fish into their tank to get them to grow. Eventually, one will get large enough that it eats the other, and Link will be granted a Piece of Heart.

The Legend of Zelda: Oracle of Seasons
A fish serves as part of the quest for the Noble Sword. If Link trades the Goron Vase to Ingo, he will give him a fish in return. This fish can be given to the man near Eyeglass Lake whose pet cat Mittens is stuck in a tree. He uses the fish to call the cat down from the tree. In exchange for this, the man gives Link the Megaphone he was using to call Mittens.

The Legend of Zelda: Twilight Princess
Several kinds of fish can be fished from various bodies of water in Hyrule once Link has obtained the Fishing Rod. By using the fishing rod in fish-infested waters, Link will usually be able to catch a fish.

The Legend of Zelda: Phantom Hourglass
Fish can be caught all over the World of the Ocean King once Link has obtained the Fishing Rod. While traveling on the Great Sea, fish-shaped spots will occasionally appear and start moving about Link's Sea Chart. When near one of the spots, Link can catch a variety of fish.