He is one of the Legendary Sannin along with Tsunade and Jiraiya, all of whom trained under Sarutobi Hiruzen (The Third Hokage).
He has a subordinate in the form of Medical Ninja Yakushi Kabuto since moving to the Hidden Sound Village, wanting to find a new body for his soul.
It was then revealed that he wanted Hidden Leaf renegade Uchiha Sasuke, who now moved to the Hidden Sound, as his vessel in the events of Shippuden.
His animal motif is a snake, often seen by extending his neck to plant a Curse Mark on someone. He wields a weapon called the Sword of Kusanagi which he can either wield from his hand or, in the events of Shippuuden, spit out from inside his body. He has a giant snake that he can summon named Manda.
