Zabuza Momochi

was a missing-nin from Kirigakure, and the first major antagonist of the series.

Background
In the past, Kirigakure had the practice of pitting Ninja Academy graduates against each other in a battle to the death for a final exam. After Zabuza, not yet a student himself, killed all one hundred of that year's students, the practice was discontinued. Zabuza would thereafter be known as the "Demon of the Hidden Mist". His fame grew over the years, as he became both an ANBU and a member of the Seven Ninja Swordsmen of the Mist. He also killed the Konohagakure ninja Kumade Toriichi. At some point he discovered Haku, a child with a special kekkei genkai and began training him to be the ultimate weapon. In time he attempted to kill the Mizukage in a failed coup d'état, and subsequently fled with Haku and some other followers, such as the Demon Brothers.

The anime adds Zabuza to scenes depicting the Kaguya clan's history. When the Kaguya attacked Kirigakure, Zabuza did not help in the village's defense. He and Haku later ran into Kimimaro. Although Haku wanted to talk to the boy, Zabuza forced him to leave Kimimaro alone and keep moving.

Personality
Zabuza was initially portrayed as aggressive, arrogant, cruel, cold and ambitious, willing to become Gatō's thug to gain enough funds to start a second coup d'etat on the Mizukage, and kill anyone who stood in his path, including plotting to kill Gatō once gaining enough funds from him. He willingly uses his own men and others as pawns to fulfill his ambitions, as he raised Haku to be an efficient tool to be discarded when he had no use to exploit; although unlike future villains, he was blunt about the purpose that his recruits were needed for, not the manipulation of pretending to be kind to inspire loyalty.

He is an observant adversary who is able to analyze his opponent's techniques after seeing it once, but becomes overconfident if he sees the technique as useless. In his last moments, it is revealed that he cared deeply for Haku, and after being convinced by Naruto Uzumaki, he sacrifices his life to kill Gatō, and dies wishing he could join Haku in the afterlife. However he seems reluctant to speak or hear about it, telling whoever does so to shut up.

He has also shown to have a sense of honor, as after his resurrection he expressed disgust about the idea of working for anyone who would stoop down so low as to use the undead for their own gain, in the meantime making the revived immortal. His sense of honor is extended even further when pleads with Kakashi to stop him and Haku from causing damage.

Appearance
Zabuza was a tall and noticeably muscular man with pale skin, short spiky black hair, brown eyes, and small eyebrows. He was normally seen wearing bandages like a mask over the bottom half of his face. Under his mask, he had a relatively narrow jawline and jagged-teeth, a trait he shared with his fellow Swordsmen. He wore his forehead protector sideways on his head, and prior to his defection from Kirigakure, donned its standard uniform and flak jacket. After his defection, and during his first appearance, he was seen bare-chested, with his chest only covered by a belt to which he attached his Decapitating Carving Knife, wearing baggy pants with the striped pattern typical of Kirigakure and mimetic wrist-warmers extending up to his elbows, with matching leg-warmers. During his second appearance, he wore an attire similar to the one his former colleague Kisame Hoshigaki wore under his Akatsuki cloak: a sleeveless black shirt and matching pants, complete with a waistguard, and yet again, Kirigakure's striped wrist and leg-warmers. In this outfit, just like the other Swordsmen of his generation, he also had bandages loosely tied around his neck like a scarf.

Abilities
Zabuza was a very vicious battler, preferring more direct attacks rather than deception, along with strong taijutsu and kenjutsu skills. Even as a child who had yet to begin in the Academy, he had enough prowess to kill 100 trained students single handedly. Kakashi notes that his Silent Killing prowess is second to none. He also demonstrated considerably great strength, able to crush solid objects like an apple when only at partial strength, and most commonly seen from his ability to effortlessly wield his large sword with a single hand, and a high degree of speed, capable of matching Kakashi in both movements and hand seals. Also, true to his moniker, Zabuza possessed an incredible amount of stamina and physical resistance: after fighting Kakashi and having both of his arms injured by many stabs, he could charge against Gatō's thugs, killing many of them with a kunai held in his mouth, and eventually, despite having a large number of spears and bladed weapons stuck in his body by the enemies, reach Gatō, killing him as well. However, despite Zabuza's aggressive nature, he had been shown to be a crafty ninja and a master of stealth and assassination with an extensive knowledge of the most vulnerable organs in the human body, renowned even amongst his fellow ANBU members, with enough skill to kill opponents through zero visibility, capable of misdirecting them.

Kenjutsu
During his time as a Kirigakure-nin, Zabuza was one of the Seven Swordsmen of the Mist, a powerful group of ninjas who employed special, massive swords in battle. Even after defecting from the village, Zabuza retained his signature weapon: the Decapitating Carving Knife, an over-sized broad sword, whose shape was thought to decapitate enemies. He was a master in its use, showing off tremendous swordsmanship capabilities, being capable of dispatching numerous enemies with a few slashes, and claiming that his sword "never cut a second time", implying to have killed a large number of people with a single attack. The weapon's weight didn't seem to slow Zabuza down at all, as he could employ it in combat for extended periods of time with no visible strain on himself, something his former acquaintance Suigetsu Hōzuki hasn't achieved. Apart from handling it very skillfully, Zabuza could also throw it spinning at several enemies. He threw it with enough power to lodge itself into a hard tree trunk.

He also wielded a kunai with a sharp protrusion on one side (which in the anime is Kirigakure's variation of the standard kunai), designed for thrusting and stabbing instead of slicing, which fit perfectly his stealthy attributes.

Nature Transformation
Likely, in part, due to him being from the Hidden Mist, Zabuza seemed to prefer water techniques, and had been shown to have great skill in them. He was especially adept at the Hidden Mist Technique, mostly because it allowed him to show at the fullest his true forte, the technique that he got most praised for during his time as an ANBU: Silent Killing. His skill at it was considered unrivaled, and he had mastered it to such an extent that Zabuza could strike his opponents without the need of sight, simply by focusing on any slight sounds made by the opponents. With the addition of the Hidden Mist Technique, Zabuza was capable of carrying out stealthy attacks even in completely open spaces, able to suddenly disappear from enemy's sight and then strike unseen. His skill with this technique was such that he could create an impenetrable mist, thick enough to almost completely prevent vision, without the need of an immediate source of water nearby.

He could perform various water-based techniques while maintaining a separate one, as seen when he kept Kakashi trapped in the Water Prison Technique while at the same time attacking the rest of Team 7 with a water clone; he could maintain several of these clones at the same time, often using them as diversions. He also showed proficiency in large-scale water-attacks from launching powerful torrents of water in the forms of dragon missiles and giant waterfalls at his opponents.

Land of Waves Arc
In order to gain funds for a second coup d'etat, Zabuza became a mercenary assassin for hire. As one of his jobs, he was hired by Gatō to kill a bridge builder named Tazuna. When the Demon Brothers were sent to eliminate Tazuna and failed, Zabuza decided to take care of him personally. Upon tracking down his target, Zabuza found that Tazuna was being protected by Kakashi Hatake and his students. Wanting to test his ability, Zabuza challenged Kakashi to a battle, and Kakashi complied by revealing his Sharingan.

Soon after the battle began, Zabuza managed to catch Kakashi off guard, and trapped him with his Water Prison Technique. Needing to stay with Kakashi to keep him imprisoned, Zabuza sent a water clone to kill Tazuna and the rest of Kakashi's team, believing it to be a simple matter. Naruto Uzumaki, however, managed to sneak up on Zabuza, forcing Zabuza to release Kakashi. Freed, Kakashi and Zabuza resumed their battle, though Kakashi's Sharingan quickly gave him the upper hand. Copying Zabuza's Water Release: Great Waterfall Technique before he could use it, Kakashi managed to defeat Zabuza.

Before Zabuza could be killed by Kakashi, however, Haku appeared, disguised as a hunter-nin, and threw two needles into Zabuza's neck, apparently killing him. Taking Zabuza's body away, under the guise of needing to destroy it, Haku revived Zabuza, the needles having been used to paralyze him. Although Zabuza's life had been saved, he needed a week to recover, and he planned to kill Tazuna and Kakashi then.

A week later, Zabuza and Haku appeared before Team 7 for a rematch. As Haku dealt with Kakashi's students, Zabuza dealt with Kakashi. Having been told how the Sharingan worked by Haku, Zabuza blanketed the area in a thick mist, to avoid falling prey to the Sharingan's influence. In doing so, Zabuza was able to slash Kakashi with his sword, greatly damaging his opponent. Kakashi, however, allowed himself to be attacked, and summoned his ninken to sniff out the blood, now on Zabuza's sword, to track and pin him down.

With Zabuza unable to fight back, Kakashi prepared to kill Zabuza with his Lightning Cutter, and charged at Zabuza. Before the Lightning Cutter could meet its mark, however, Haku appeared as a human shield, and took the full force of the attack, fulfilling his promise of being a tool for his master. Freed as a result of Haku's intervention, and not willing to allow the opening Haku had created to go to waste, Zabuza tried to slash through Haku's body to kill Kakashi, though Kakashi was able to avoid it and disable Zabuza.

With Zabuza no longer able to battle, Gatō arrived, and revoked their agreement so that he could have his own henchmen kill Tazuna instead. No longer having a reason to kill Tazuna, Zabuza ended his battle with Kakashi, although Naruto was not satisfied by this. Angered that Haku died for Zabuza, while Zabuza had shown no signs of remorse, Naruto lectured him on the feelings Haku had for him, and the loyalty he felt towards Zabuza.

Brought to tears by Naruto's words, Zabuza revealed that he really did care about Haku, and valued him higher than a simple tool. Wanting to repent for what he had done, Zabuza took one of Naruto's kunai, and charged through Gatō's men to get to Gatō, being stabbed multiple times along the way. Upon reaching Gatō, Zabuza killed him, and collapsed due to his injuries. As Gatō's men fled, Zabuza asked Kakashi if he could be brought to Haku, to which Kakashi complied. Being by Haku's side in death, as Haku was by his in life, Zabuza, as he passed out, wished that he could go to the same place as Haku. Kakashi believed that they would be able to go to that place together. After mourning his and Haku's deaths, Team 7 buried them next to each other, with the Decapitating Carving Knife stabbed into the ground.

Shinobi World War Arc
Zabuza is resurrected by Kabuto, along with other famous shinobi through the Summoning: Impure World Resurrection, to prepare for war. While marching for war, he and Haku realized they were not in the afterlife anymore. Gari explained the situation, leaving Zabuza angry because he didn't want to obey someone who would stoop low enough to use the dead.

When his group was attacked by the Surprise Attack Division, Haku raised an ice dome to protect them. Zabuza noted he didn't need to do it, noticing the other members of the group regenerating, mentioning that not only were they brought back, but they were made impossible to kill. Haku attacks the Surprise Attack Division from above and him, Zabuza, Gari, and Pakura were about to kill them until the Third Division arrives and Kakashi saves Sai from Zabuza, who didn't expect fighting Kakashi again. He greets Sakura and notices how much she has grown since they had last met. Zabuza asks Kakashi and Sakura of Naruto's growth and learns how famous he became since his death.

When Kabuto strengthens his control over the Impure World Resurrection summons, Zabuza pleads with Kakashi to stop them. Soon afterwards he engages Kakashi in combat while the other resurrected ninja attack the rest of the Third Division. In the midst of the battle Gari and Pakura summon the previous generation of the Seven Ninja Swordsmen of the Mist, and Zabuza joins them in the middle, wielding his broken Decapitating Carving Knife. During the battle Zabuza attacks many shinobi and uses the iron collected from their blood to reform his carving knife. Kakashi moves in to strike him with a raikiri, but once again Haku takes the blow. Zabuza then moves in to cut clean through Haku and attack Kakashi.

Legacy
Following Zabuza's death, Kirigakure ninja began associating him with members of Team 7; Kisame Hoshigaki referenced Zabuza when he first met Kakashi, while the Fifth Mizukage and Chōjūrō believe Sasuke was the one who defeated him and Haku.

Zabuza's sword is taken from his grave site in Part II by Suigetsu Hōzuki (or Tenzen Daikoku in the anime, but then retrieved by Suigetsu later).

During his and Kakashi's exchange following Zabuza's resurrection, Kakashi admits that it was because of him and Haku that Naruto strove to become the ninja and hero that he is.

Trivia

 * Zabuza's surname, "Momochi", might be from the famous ninja, Momochi Sandayū, although his name is written in different kanji.
 * Zabuza's first name means "never cut twice" in Japanese, while his surname, "Momochi", means "peach earth" in Japanese.
 * Despite his short appearance in the series, Zabuza was still very popular in the character popularity polls.
 * In some scenes of the anime, Zabuza did not have any eyebrows. He was called eyebrowless by Naruto several times, even giving him the Nicknames 'no-brows' or 'eyebrowless freak'.
 * Zabuza made a cameo appearance in a omake Naruto Shippūden episode, appearing on a lantern.
 * He also made a cameo in a crowd shot in Naruto Shippūden episode 183 alongside Haku, Hayate Gekkō, and several Rain Ninja.
 * According to the Naruto databook:
 * Zabuza has completed 191 official missions in total: 4 D-rank, 67 C-rank, 79 B-rank, 29 A-rank, 12 S-rank.
 * Zabuza has been shown to emanate a shroud of chakra that takes the form of an oni-like creature, which might have been where his nickname originated from.

Quotes

 * "When I was your age, my hands were already soaked in blood..."
 * (To Kakashi) "You're right. Those little people and their little dreams, why should I care about them?! I have my own dream!"
 * (To Team 7) "When you've hovered between life and death so many times that it doesn't faze you, you may be called a ninja. When you've become so deadly that your profile has been entered into my bingo book, then you may have earned the title ninja."
 * (To Naruto) "Your words cut deep, deeper than any blade."
 * (After expressing feelings for Haku and removing his mask)" Well? Cat got your tongue? Are you so surprised to discover that I'm human? Even shinobi are human. No matter how hard we try, we always fail to escape that simple fact. Well at least, I have failed."
 * (To Gatō) "Uh uh...I won't be joining Haku. Where he's gone I cannot follow. We wouldn't be welcome where Haku's gone to. Hell's where WE'RE going, Gatō!"
 * (To Gatō) "Even the unremarkable Demon of the Hidden Mist can die and become a real Demon in hell!"
 * (To Gatō, about Hell) "I can't think of a more fitting destination for a demon ninja, can you?! I'm told there are many demons down there - of all shapes and sizes! Oh yes, I should fit right in! You, on the other hand, Gatō... Well,I fear you're in for a long and very painful eternity!"
 * (Last words to Haku) "You were always at my side, the least I can do is to be beside you at the end. I know it cannot be, but I wish I could go to where you have gone. How I wish I could join you there, Haku."
 * (To Kakashi)