Helmasaur

Helmasaurs are recurring enemies in the Legend of Zelda series. They are portrayed as small beasts, protected by an armor shell which fails to mask its backside. In its appearances, attacking its exposed backside provides a successful method of killing it. Still, some games give Link the ability to forcibly remove its protective casing, making its body entirely vulnerable.

The Legend of Zelda: A Link to the Past
Link can either use a Bomb or the Magic Hammer to destroy their securing masks, penetrating their defenses and rendering them easily defeated through means of Link's sword. A considerably stronger Helmasaur, Helmasaur King, is the boss of the Palace of Darkness.

The Legend of Zelda: The Minish Cap
Helmasaurs are agile, tiny red creatures with metallic conical helmets and the feet of a chicken. As usual, the enemies could be destroyed by striking its rear, but using a Gust Jar removes its armor, making slaying them a less of a chore.

The Legend of Zelda: Twilight Princess
Helmasaurs are brown creatures with a dark swirl present on their unprotected thighs. If they are to take notice of Link, they will charge at him, squealing violently in the process. They first appear in the Lakebed Temple, where at first Link can only kill them by slashing their backside due to their strong shells. He then later acquires the Clawshot, which grants him the ability to forcibly remove their shell, rendering them defenseless and allowing Link to attack them more directly. Helmasaurs can also be spotted throughout Hyrule Field and in the City in the Sky. Another version of the Helmasaur, the Helmasaurus, is also present in the game.

Link can use the Helmasaur's shell to weigh down switches when nothing else is available, or if the number of other heavy objects fall short.