Zabuza Momochi, a missing-nin who originated from Kirigakure.
Missing-nin (抜け忍, nukenin, English TV: Rogue Ninja, literally meaning: runaway shinobi) are ninja who abandon their village with no intention of returning. Missing-nin are criminals in effect, if not before their defection then certainly after abandoning their duties. As such, missing-nin are listed in their village's Bingo Book to be killed on-sight;[1] Kirigakure's hunter-nin are specifically assigned to eliminate these missing-nin. Although some missing-nin may continue wearing their village's forehead protector, they no longer swear allegiance to their village; members of Akatsuki - most of them missing-nin - carve scratches across their forehead protectors to symbolise they have rejected their village.
Leaving the village does not necessarily automatically make one a missing-nin. Tsunade withdraws from life as a ninja and departs from Konoha following the Second Shinobi World War, but she is at no time considered a missing-nin by the village. Jiraiya informs her, however, that if she aids Orochimaru - an enemy of Konoha - that her status will change and he will be forced to kill her.
Likewise, being branded a missing-nin does not guarantee their former village will seek them out as a criminal. Itachi Uchiha becomes a missing-nin after the Uchiha Clan Downfall, but he does so under orders of Konoha's leadership; while most of Konoha's population does indeed consider Itachi a criminal and treats him as such, its leaders are privately aware that he remains loyal to Konoha. Similarly, when Sasuke Uchiha defects from Konoha and becomes a missing-nin, the Fifth Hokage decides not to pursue him as a criminal as a favour to Naruto Uzumaki. The Sixth Hokage Candidate later withdraws this leniency and orders his execution.[2] For his help during the Fourth Shinobi World War and the good word of the Sixth Hokage, Sasuke is ultimately pardoned for his crimes.[3]