Koloktos

Koloktos is the boss of the Ancient Cistern in Skyward Sword. It is a "massive metallic weapon created to punish intruders". Ghirahim overtook it and supplied it with cursed energy, giving it more power to battle against Link. It is held together by red cores in its arms and torso.

Strategy
Aware of its weakness, Koloktos covers its torso with its bottom two hands. The top two arms sometimes throw sharpened blades at the young hero, which he can dodge or block with his shield. When Link is near the automaton, it tries to crush him with its giant arms. By dodging this attack and using his whip, Link can remove the cores from its arms, making them collapse on the floor. Koloktos will eventually use its lower hands to attack, giving the hero a chance to attack its chest core. Koloktos will reanimate its missing arms and try to damage Link again.

After the boss has suffered enough damage, it pulls itself out of the ground and reveals its legs, giving it the ability to chase Link around the room. It also pulls out six cutlasses and cages its chest core to prevent Link from attacking it. The contraption will sometimes try to damage the hero with a barrage of slashes, which he can dodge by running away. It can also summon 3 Cursed Bokoblins which can be destroyed with a few sword swipes. After dodging an attempted strike, Link can pull the core out of one of its arms as he did with its first form. He can then pick up the boss' cutlass and use it to destroy his various parts. If Link manages to break off its arms, Koloktos will charge at Link, which Link avoids causing Koloktos to get dizzy. Link must then slice its legs apart with a cutlass, then slash the grate of his chest so he can attack his core. Once this is done three times, Koloktos will fall apart.

Trivia

 * Koloktos's overall design seems to take inspiration from Hindu deities, particularly the Vamana avatar of Vishnu.
 * Koloktos is a homogram of colossus, meaning "huge". This is true to Koloktos's height. Its name may also be derived from "koło ktoś", a Polish phrase meaning "Round One". This applies to its round torso and orb-like red cores.
 * Koloktos is one of the only bosses that does not completely explode. The darkness inside it explodes while it's golden armor pieces stay behind.
 * At the beginning of the fight, Koloktos's facial expression is neutral. The more it is attacked, the more it's face seems to twist into a mischievous smile. Furthermore, when Koloktos is defeated, it seems to laugh like a child before exploding.
 * Koloktos is the third boss involving Ghirahim in its introduction.
 * Even though it has a cage to cover its weak spot, it only uses it once Link has damaged it considerably.
 * Koloktos can be damaged with Link's regular sword even during the second phase of the fight, but it will not die until its core is struck at least once with its own sword, even if its health is at zero.
 * If Link returns to the boss room, he will still be able to use Koloktos's swords, but he won't be able to exit the room with them.