A large boss fight encountered in the Gamecube game Metroid Prime 2. Commonly considered a very impressive boss by Metroid standards, rivalling Kraid for size.

Envisage the head of a giant robotic Sam Fisher attached to the top of an also-giant robotic tarantula, with four legs removed and the others replaced by bits of an arbitrary Decepticon. From somewhere on the assemblage comes beams of antimatter and the tarantula's projectile hairs are homing missiles. You now have a clue.

Technically the legs are used to locomote, but the typical player does not actually notice Quadraxis moving because the lock-on point is so high above the ground, you cannot see it.

It is based upon a smaller enemy, which is simply called a 'Quad'. Quads have a habit of spinning around very rapidly en pointe while a cloud of electrical arcs surrounds their legs. To many a player's great disturbance, Quadraxis also performs this attack, complete with miniature lightning storm. In a claustrophobic circular room.