Rat

Rats are enemies found in many games in the The Legend of Zelda series. While given a generic name in English, they are distinct from "normal" rats in Japanese in a similar manner to Keese from "normal" bats. Generally, they are found in dark, underground locations, and tend to run around in swarms while squeaking.

The Legend of Zelda: A Link to the Past
In The Legend of Zelda: A Link to the Past, Rats are found in the passage between Hyrule Castle and the Sanctuary. They run around the room, typically along the edges of walls and land beside pools of water, occasionally stopping. They are extremely weak, though their size and speed and the darkness where they are found may lead to Link accidentally running into one. Their Dark World counterpart is the Bazu, a katydid-like creature that appears in the well-lit highest story of Thieves' Town.

The Legend of Zelda: The Wind Waker
In The Legend of Zelda: The Wind Waker, Rats reappear with a stylized, vaguely-anthropomorphic design. They run around the rooms they are in and can climb walls. They also travel into holes in the walls; if Link throws some All-Purpose Bait in front of one of these holes, a Rat will offer to sell him an item. Rats also appear in the dead ends in the crawlspace maze in Tingle's cell, where they pull on a rope that activates a trapdoor under Link, dropping him into the water under Windfall Island. Normal Rats are a reddish tan color with dark gray facial markings. However, there is also a dark gray type with red facial markings that throws bombs, known as the Bombchu.

The Legend of Zelda: Four Swords Adventures
In The Legend of Zelda: Four Swords Adventures, Rats appear as they do in A Link to the Past, though they are blue. They first appear in the Cave of No Return. The Bombchu explosive also appears as an enemy.

The Legend of Zelda: Twilight Princess
In The Legend of Zelda: Twilight Princess, Rats are fairly realistic-looking aside from their gigantic size. They are first found in the first Lantern Cavern and later appear in the underground waterway. They attack Link by leaping at him. When under the effects of Twilight, Rats are turned into an octopus-like creature called Shadow Vermin, which are additionally capable of skimming across water. There is also an invisible, ghostly type of rat called a Ghoul Rat that grab onto Link en masse and make movement difficult, and can only be seen with Wolf Link's senses.

The Legend of Zelda: Phantom Hourglass
In The Legend of Zelda: Phantom Hourglass, Rats are purple and display none of their anthropomorphic qualities from The Wind Waker, instead being more like the ones in A Link to the Past. They are first found in the caves of Mercay Island and run around the room aimlessly. There is also one specific Rat with a Small Key attached to its tail that runs between two wall holes in an arc-shaped room, dashing the other way if Link approaches. To defeat it, he must cover one of the holes with a movable block and corner it when it comes out from the other.

The Legend of Zelda: Spirit Tracks
In The Legend of Zelda: Spirit Tracks, Rats look and act like they do in Phantom Hourglass. However, Phantom Zelda is terrified of them and refuses to move if any are nearby. Additionally, Chancellor Cole spawns several spectral white Rats during the battle atop the back of the Demon Train, which must be defeated before they reach Zelda, lest Cole take control of her armor like a puppet.

The Legend of Zelda: A Link Between Worlds
In The Legend of Zelda: A Link Between Worlds, Rats appear in the same capacity they do in A Link to the Past. Their Lorule counterpart is the Dark Rat, which is stronger and yellow.

The Legend of Zelda: Tri Force Heroes
In The Legend of Zelda: Tri Force Heroes, Rats look and act as they do in A Link Between Worlds, and are found both in the Ice Cavern and the Ruins. Their colors are subtly different between the two areas (with the former being lighter and cyan-tinted), but otherwise they are the same. In the Ice Cavern, they are sometimes trapped in snowballs.