Hanzō (半蔵, Hanzō), feared as Hanzō of the Salamander (山椒魚の半蔵, Sanshōuo no Hanzō), was a legendary shinobi, and the leader of Amegakure during his lifetime.

At some point during Hanzō’s childhood, he found a black salamander with deadly venom residing in his village. When it died, its venom sac was embedded into his body in the hopes of creating a venomous ninja who himself was immune to toxins. This required him to wear a mask constantly, in order to protect others from his venom-laced breath. At some point after this, Hanzō became well known and renowned throughout the shinobi world, so much that enemies have been known to flee at the very sight of him.

At one point, Hanzō confronted dozens of Samurai from the Land of Iron, who retreated after realising who they were up against except for one. Hanzō fought Mifune, whom he defeated and in the process, poisoned in their final clash by slashing his head. Hanzō spared his life, due to the samurai’s strength and faith. He went as far as giving him the antidote to his poison to give him a fighting chance, but then left without treating Mifune’s injury. Despite claiming to think he had killed him, in the back of his mind, Hanzō knew Mifune was still alive.