Hanzou

半蔵

Hanzou (半蔵), also known as Hanzou of the Salamander (山椒魚の半蔵, Sanshouuo no Hanzou), was a legendary ninja and the former leader of Amegakure. He was extremely security-conscious, guarded twenty-four hours a day, and subjected anyone wishing to see him to thorough searches. He rose to fame around the time of the Second Great Ninja War. Little is known about his abilities, aside from his habit of riding on the head of a giant salamander (presumably a summon), but he was so powerful that he, along with his summon, fought off all three Sannin. After their battle, he was so impressed by their strength that he decided to spare them if they agreed to accept the title of Konoha's Legendary Three Ninja (伝説の三忍, Densetsu no Sannin); this makes him responsible for naming the trio. Being capable of defeating all three Sannin head-on, Hanzou is easily a kage-level ninja. His power was such that Jiraiya expressed intense shock upon hearing that Hanzou had been defeated by Pain.
Hanzou's insecurities later got the better of him when a group of ninja, led by Yahiko, Nagato, and Konan, began a quest to end war through unorthodox means. He viewed these ninja as a threat to his power and sought to get rid of them. He then teamed up with Danzo, the leader of ANBU Root, to kill the group's leader, Yahiko, in a treacherous manner. He was later single-handedly killed by Pain (under unknown circumstances). The hatred that Nagato held for him for causing Yahiko's death was so severe that he conducted a systematic genocide on anybody even remotely associated with Hanzou (with the exception of Danzo, who somehow escaped the carnage).