A Combination Transformation where man and beast become a single entity. It is a specialty of the Inuzuka clan, a clan that has been walking side by side with ninken for generations. They coalesce into a bicephalous wolf, thus drastically increasing their power. In their direct attacks, they demonstrate great efficiency. Furthermore, using techniques in addition to this gives birth to an extraordinary power of destruction.
In the manga and anime, Kiba calls this technique by its full name, Inuzuka-Style: Human Beast Combination Transformation: Double-Headed Wolf (犬塚流・人獣混合変化・双頭狼, Inuzuka-Ryū: Jinjū Konbi Henge: Sōtōrō). The databook entry for this technique drops the "Inuzuka-Style" part.