Zabuza Momochi

Zabuza Momochi is the secondary antagonist of the Land of Waves arc in Naruto and a minor antagonist in the Fourth Great Ninja War arc. He is a rogue ninja from the Hidden Mist Village hired by Gatō to kill Tazuna before he can finish building the bridge that will break Gatō's control over the Land of Waves.

Trivia

 * Altough Gatō was the Land of Waves arcs main antagonist Zabuza serves as Naruto's first major enemy in battle due to the fact that Gatō doesn't fight.