A supporting character from Naruto otherwise known by his nickname Pervy Sage (エロ仙人, ero sen'nin).
He is one of the Legendary Sannin along with Tsunade and Orochimaru, all of whom trained under Sarutobi Hiruzen (The Third Hokage). He is the mentor of Namikaze Minato (The Fourth Hokage), and later Uzumaki Naruto.
His animal motif is a frog, mostly shown by summoning Gamabunta.