Terrorpin

Terrorpins, also known as Turtles or Shell Spinners, are a hard-shelled species of turtle that debuts in The Legend of Zelda: A Link to the Past. Their carapaces are absolutely impenetrable, and unlike the similar Hardhat Beetle they give no recoil upon being hit. A sufficient amount of force to the ground near them can cause them to flip onto their backs, exposing their weak plastrons. However, this occurring while they are already on their back will right them, so care should be taken when dealing with groups of them.

The Legend of Zelda: A Link to the Past
In The Legend of Zelda: A Link to the Past, Turtles have red shells and first appear in the Palace of Darkness, where they generally wander aimlessly, but attack Link when he is close. They also commonly appear in the darker rooms of the palace, thus making it easy to accidentally run into one if the lantern is not equipped. They are completely invulnerable until Link obtains the Magic Hammer item, allowing them to be flipped over.

The Legend of Zelda: Four Swords Adventures
In The Legend of Zelda: Four Swords Adventures, Terrorpins come in multiple sizes and a variety of colors, each of which denotes which Link can defeat them. The yellow ones may be defeated by any Link, while the differently colored ones require the corresponding Link. They first appear in the Temple of Darkness, itself seemingly a substitute for the Palace of Darkness. They also are the focus of a minigame in Frozen Hyrule called Terrorpin Hockey.

The Legend of Zelda: Phantom Hourglass
In The Legend of Zelda: Phantom Hourglass, six Shell Spinners reside in Mutoh's Temple, coming in two groups of three. They unusually have turquoise shells with small, rivet-like bumps on them, likely to make them look reinforced. They also have black bodies and pink eyes. The first time Link encounters them, he will not have the hammer yet, and as such they must be avoided. Once it is obtained, he can defeat them as normal.

The Legend of Zelda: A Link Between Worlds
In The Legend of Zelda: A Link Between Worlds, Terrorpins resemble their design in A Link to the Past, but with more plates and a withdrawn head showing eyes glowing from the front of the shell. They now debut in the Tower of Hera, which requires extensive use of the hammer in this game.

The Legend of Zelda: Tri Force Heroes
In The Legend of Zelda: Tri Force Heroes, Terrorpins look and act as they do in A Link Between Worlds, debuting in Silver Shrine. Additionally, if a Wallmaster falls near one, the force of impact can flip it over too.