Meizu

and his brother Gōzu are twin brothers and former Kirigakure Chūnin.

Background
They fled the village with Zabuza Momochi when he failed in his attempt to kill the Mizukage, and thereafter began working for him as assassins.

Personality
Meizu is described as having a short fuse and is extremely violent while torturing his foes.

Appearance
Meizu wears an air-mask similar to Kigiri's and a large clawed poisonous gauntlet on his left arm wear he projects his shuriken chain. He also wears camouflage pants like Chōjūrō and a Kirigakure headband with two horns on it.

Abilites
Gōzu and Meizu are a paragon of coordination attacking. His large metal gauntlets house a retractable shuriken chain running between the two of them, which they can use to bind an enemy and then slice them to pieces. In the event that the shuriken chain is neutralized, Gōzu also has a release mechanism to free him from Meizu for individual attacks. He uses the sharp, poisoned claws on his gauntlets to shred his foes.

Land of Waves arc
At the start of the series Zabuza sends them to kill Tazuna, but they are stopped and by Kakashi Hatake, Tazuna's bodyguard. He ties them to a tree so that they can later be taken into custody.

Trivia

 * Strangely enough, even as a Missing nin, Meizu lacks the scratch on his headband signifying his status as a Missing nin. Zabuza seems to share this as well, which possibly implies that they have loyalty to the village but not to the Mizukage himself.