An Armos is a fictional, animated statue in The Legend of Zelda series. An Armos typically poses as a statue or suit of armor, but attacks when approached.
The Legend of Zelda
The original Armos in The Legend of Zelda resembles a suit of armor. They appear near Death Mountain, where they are orange, the Lost Woods, where they are green, and in the graveyard where they are white. Some Armos move fast, others move slow. Armos occasionally cover a hidden staircase that could be revealed by touching the Armos, causing it to move. One hides the power bracelet which can be used to move rocks to reveal a series of hidden staircases to move through the land quickly.
The Adventure of Link
The sequel, The Adventure of Link, does not feature Armos. It is the only main Zelda game to not do so, but the Iron Knuckle knights serve the same role at palace entrances (they also serve the Darknut role inside palaces). Some knight statues that can be brought to life by Link's sword, while others drop a red magic bottle to provide a full magic refill.
A Link to the Past
In A Link to the Past, Armos only appear in the Eastern Palace area, standing dormant until bumped into, which causes it to bounce towards Link. Unactivated Armos are grey, oval-shaped statues, but change to light brown when awakened. Certain skull-like rocks in the Dark World will animate if they are touched, which behave similarly to the Armos.
Armos Knights/Death Armos
Armos Knights are the boss of the Eastern Palace. They are similar to other Armos, but are bigger and blue, and angrily stomp around the room, trying to crush Link. They also appear as a mini boss in Ganon's Tower.
In Link's Awakening, Armos and one single Armos Knight appear in the Face Shrine and in the shrine to the south. The Armos are similar to those from The Legend of Zelda, except these do not move as fast. They often hide among similar looking statues. Many statues resembling Armos form a maze near the shrine to the south of the Face Shrine, but one in a few are true Armos. Each wall has one Armos that must be found to reach the Shrine.
Inside the Shrine, an Armos Knight guards the Face Key. His main attack is slamming the ground to paralyze his foes.
Ocarina of Time/Majora's Mask
In Ocarina of Time and Majora's Mask, Armos mostly appear in dungeons, and are giant, grey, aged statues that look somewhat like chess pieces. Some look the same as regular inanimate statues, making them more dangerous. Actual statues can be pushed around, but Armos Knights attack when approached. A bomb or the Megaton Hammer will destroy one. When defeated, they will jump wildly around the place and explode. In Majora's Mask, Armos only appear in the Stone Tower Temple.
Also in Majora's Mask, the Death Armos appears again in Stone Tower Temple, albeit with a different look than in A Link to the Past. The Death Armos appears as a floating statue with a light sensitive panel on each of its four sides. When one of these panels is struck by a Light Arrow, the Armos turns upside down. Death Armos attack by attempting to crush Link, but a Death Armos that attacks while flipped smashes its own head and explodes.
Oracle of Seasons and Oracle of Ages
In Oracle of Seasons and Oracle of Ages, Armos Knights are exactly as those from Link's Awakening, as Flagship built upon data from that game. They are in no specific area, and as in Link's Awakening, they can be destroyed with a Boomerang, or a bomb. Swords are ineffective unless paralyzed by a boomerang.
Armos Warrior is the sub-boss of the Skull Dungeon in Oracle of Ages. He resembles a large knight with a sword and shield. His sword has a life of its own, which locks onto Link and charges at him. After his sword and shield break, he begins charging at Link.
The Wind Waker
In The Wind Waker, Armos come in small and large forms. When Link enters a room, the small Armos activate and bounce quickly towards Link. They can be paralyzed by an arrow in the eye and striking the crystal on the back will cause them to spin around wildly and self-destruct (note: the arrow isn't a necessary weapon, it makes it easier to access the weak point).
The Armos Knights are gigantic statues that will slowly bounce towards Link when he approaches. To defeat one, Link must throw a bomb into its mouth, which opens occasionally, or can be made to open by shooting its eye. After the bomb has been thrown, the Armos Knight spins around and self-destructs.
The Minish Cap
The Armos in The Minish Cap are slightly different from previous Armos. While reminiscent of Armos from Link's Awakening, they are powered by flames inside their heads, and only a Minish-sized being can turn the flame off. Their figurine mentions that the Armos where created by the Minish for the Wind Tribe. When Link approaches, the Armos usually activates and quickly runs towards him, occasionally pausing. Sometimes Link must activate an Armos to clear a path and other times he must deactivate one to prevent it from blocking a path.
Armos in Twilight Princess wield hammers and look very different from those in previous incarnations, probably most resembling Moai statues on Easter Island. When animated, their facial features are clearly outlined by a glowing blue color. As in The Wind Waker, they are defeated by striking the weak spot on its rear. A bomb arrow will instantly send an armos into self-destruct mode, as will a clout from the animated statue Link must guide through the Temple of Time.
Interestingly, one of the beta enemies was called an "Armos Titan", but never made it into the final version.
In Phantom Hourglass, Armos appear in the Goron Temple. They are used to weigh down switches, after they are rendered immobile.