Chain Chomp

Chain Chomps are a dog-like species that appears in several The Legend of Zelda games, starting with The Legend of Zelda: A Link to the Past. They are from the Mario franchise.

The Legend of Zelda: A Link to the Past
In The Legend of Zelda: A Link to the Past, Chain Chomps appear in Turtle Rock, where, much like in the Mario games, they lunge at the player, only to be halted by their chains. Unlike other games, their mouths are constantly open and they seem to only have teeth on their upper jaws.

In the Game Boy Advance version, Chain Chomps also appear in the Palace of the Four Sword. Unlike most other enemies their, they use the same colors as they otherwise do.

The Legend of Zelda: Link's Awakening
A Chain Chomp, called BowWow (also formatted as Bow Wow), appears as a pet of Madam MeowMeow in The Legend of Zelda: Link's Awakening, and has its own photo in The Legend of Zelda: Link's Awakening DX. After completing Tail Cave, a gang of Moblins kidnaps BowWow. After rescuing BowWow, Link must take BowWow on a walk eventually leading to Goponga Swamp, and allow him to eats the Goponga Flowers in front of Bottle Grotto. In Madam MeowMeow's house are two Mini Bow-Wows, later named ChowChow and CiaoCiao.

In the Nintendo Switch remake, he is still referred to as BowWow, despite the other alternatively named Mario enemies having theirs changed to the standard ones. A BowWow figure is a prize in the Trendy Game, and can be placed on a stand in Madam MeowMeow's house.

The Legend of Zelda: Four Swords
In The Legend of Zelda: Four Swords, BowWow is a rare item and acts as he did in The Legend of Zelda: Link's Awakening. He is called a Chain Chomp in The Legend of Zelda: Four Swords Anniversary Edition, and appears in the Link's Awakening-inspired area in the Realm of Memories, fittingly in Goponga Swamp.

The Legend of Zelda: Four Swords Adventures
In The Legend of Zelda: Four Swords Adventures, a Chain Chomp appears as an enemy in the corrupted Kakariko Village. Its sprites resemble retouched versions of those from Link's Awakening, and it uses the same dog bark that they have used in Mario games since Super Mario 64. It appears in a maze of fences and fire reachable after all of the thieves have been caught. Once the fire is put out, it can be reached.

Hyrule Warriors
In Hyrule Warriors and its reissues, a Chain Chomp appears as the Ball and Chain for the third level of gauntlet, the Power Glove. The Chain Chomp's appearance notably does not resemble its current Mario design, but rather the design from most Nintendo Gamecube games prior to Super Mario 64 DS, such as Mario Kart: Double Dash!!

Trivia

 * Chain Chomps were originally designed for the The Legend of Zelda series, but the concept ended up first appearing in the Super Mario series. Allegedly, Takashi Tezuka later decided to put one in The Legend of Zelda series as a joke.