Octavius (Full name: Octavius Orbirus Matrix) (Japanese version オクタウィウス Okutau~iusu) is an Aquos Krakenoid of Matrix, as well as a member of the Brotherhood of Matrix, Omnicron's and Alariatte's children. He is also considered the captain of the Matrix Regiment's guards.
A silent and secretive being, Octavius is extremely intelligent, and very patient. He is almost unable to lose his temper, but when he does, he is a completely different Bakugan. Octavius is actually a kind and wise Bakugan, often giving advice to others in dire need of it. He is also portrayed as a forgiving character, as he usually forgives anyone who has done wrong to him.