The Scyphozoa is a monster designed by XANA. It can be used for three purposes: stealing someones Memory/Digital Genetic Code, attacking the Skidbladnir by draining the power from its energy shields, or possessing someone on Lyoko by implanting a virus into them.
The Scyphozoa originated from Carthage, making it possibly the first monster to come into existence, as it is by far the most important. The Scyphozoa, unlike other monsters, levitates instead of walking or rolling which is likely to allow it to travel between the sectors (see below). Its tentacles' main function is to pick up victims and steal their memories or possess them. The Scyphozoa mainly goes after Aelita, but it also stole Yumi's Genetic Code so she couldn't rematerialize in Missing Link. The Scyphozoa has not captured any of the male Lyoko Warriors, except for William in the episode Final Round. It wraps two tentacles around the victim and renders the victim immobile with a red aura, then it places three of its tentacles at the victim's head: two at the temples, and the last one at the forehead. It first appeared in Unchartered Territory when XANA captured Aelita and took her to Carthage.
The Scyphozoa made its first reappearance in the third series in Lyoko Minus One when it came from behind the activated tower, chased Aelita to the edge and grabbed her, implanting a XANA Virus in her, giving XANA full control of her. XANA then ordered Aelita to the Way Tower in the Forest, where she entered CODE : XANA on the interface, causing the Forest Sector to automatically delete itself. XANA repeats this method two other times: in the episode The Pretender to destroy the Desert sector and in the episode Double Trouble to destroy the Mountain sector. Aelita purposefully destroys the Ice Sector to return power to the supercomputer in Sabotage. The Scyphozoa also appears in Triple Trouble to possess Aelita, but fails.
The Scyphozoa next appeared in Final Round, where it took control of William. Unlike Aelita, who is released from XANA's control after she has entered CODE: XANA into a Way tower, William remained under XANA's control until Team Lyoko managed to set him free in the episode Down to Earth.
The Scyphozoa made its first season four reappearance in The Lake to attack the Skidbladnir, and it's second reappearance was in season four in Wrong Exposure, when XANA attempts to control Aelita and force her to jump into the Digital Sea. This was the last time the Scyphozoa was ever seen.
Until the middle of season four, the Scyphozoa was the only one of XANA's monsters that hadn't been destroyed, despite that it had been shot by laser arrows, Yumi's fans and even the Flying mantas' mines. The Scyphozoa finally met its doom in The Lake when a major discharge of energy from a program that Aelita activated to support the Skid's shield caused the Scyphozoa to be blasted away. It does retreat when attacked, however, which may mean it's not invulnerable to their weapons, just that it has an extremely high amount of Life Points.
