Kolossus

The Kolossus (fr: Kolosse) is the largest and most powerful monster created by Xana, larger than the towers on Lyoko and strong enough to push them over barehanded. The Kolossus is created using the combined power of hundreds of supercomputers that Xana has control over. It resembles a golem made of hardened lava, with the molten kind flowing through its body like blood. Its head somewhat resembles an insect, with two loose mandibles hanging from its chin. Several dreadlock-like extensions also come out from the top. The Kolossus is said to be from the Volcanic sector despite how its created in the show, which is only available in the video games. The Kolossus has five eyes of Xana on its body: there is one on its head, one centered on its sword arm, and three smaller ones clustered around the latter. Hitting either eye has no effect on the creature, but hitting both large eyes destroys it. When it dies, the lava portions of its body harden, leaving a frozen corpse behind. This was proved on the episode "Fight to the Finish", when Ulrich stuck one of his swords into the Kolossus' head, and then fell off, hitting the Kolossus' Sword-Arm and when the others went in the Transport, the Kolossus fell on Ulrich, devirtualizing him. It is believed that the Kolossus' corpse disappears after a short period of time, like the other monsters.

The Kolossus has no visible laser weapon. Instead, it causes devirtualization by either stepping on its foes, landing on them, or swiping at its enemies with its giant sword-like hand. The Kolossus uses no strategy in battle; its only function is to devirtualize the warriors and to destroy the Skid. While powerful, its size prevents it from attacking rapidly, so other monsters are occasionally deployed alongside it to pick off any warriors it fails to devirtualize. Also, due to its immense size and space, its deployment is limited only to a battlefield large enough to accommodate it — namely the Ice Sector.

In order to destroy it, one would have to simultaneously hit the Eye of XANA on its head and its arm. Ulrich managed this feat in Fight to the Finish, thus destroying it. The Kolossus will appear in Code Lyoko DS 2.