Piranha

Fish, also formatted as fish , are jumping, piranha-like enemies that appear in swampy areas in The Legend of Zelda games. When submerged, their dorsal fins poke above the surface of the water.

The Legend of Zelda: Link's Awakening
Fish first appear in The Legend of Zelda: Link's Awakening, in Goponga Swamp, and later appear in certain tunnels like the one leading to Animal Village. They move left and right in a set pattern and jump when Link approaches. They can only be defeated when above the water. There is an unused graphic for a vertically-oriented fin, though there are no jumping graphics. They have large eyes, a dark upper half which is green in re-releases, a light lower half to their bodies, and mouths that appear to have large lips and pointed teeth. In the remake they only have pointed teeth without lips.

The Legend of Zelda: Oracle of Seasons
Fish reappear in The Legend of Zelda: Oracle of Seasons. They appear in Eyeglass Lake, where they look and act the same as previously, but are tinted orange. They are sometimes found in deeper waters.

The Legend of Zelda: Four Swords
Fish, now called Fin Piranhas, reappear in The Legend of Zelda: Four Swords, in Talus Cave, where they have a different design with an angled, gray body and red underside. They are more aggressive than in previous games and chase Links that are close to them, regardless of direction, and are quicker while chasing. In The Legend of Zelda: Four Swords Anniversary Edition, they appear in the Realm of Memories's Link's Awakening area, in Goponga Swamp.

A variant of the Fin Piranha from this game, called Cloud Piranha, appears in The Legend of Zelda: The Minish Cap.

The Legend of Zelda: Link's Awakening

 * Player's Guide: "These fish have an appetite for heroes. Luckily, they have the brains of fish. Use your Sword to finish them off."