Black Zetsu

is half of the duo of Zetsus. An artificially created human that works in the service of Akatsuki, Black Zetsu was created from the will of Madara Uchiha.

Background
When Madara was on the verge of death, he manifested his will and covered one half of White Zetsu with it, creating Black Zetsu. This in turn made the complete Zetsu partially a clone of Madara, albeit weaker. Both halves later accompanied Obito to Amegakure to locate Nagato, who had unknowingly been given Madara's Rinnegan as a child. Zetsu then accompanied Obito as he approached the orphans, introducing himself as Madara Uchiha.

Personality
Compared to White Zetsu, Black Zetsu, nicknamed, is more serious and knowledgeable, befitting a bearer of Madara's will. In the Japanese version of the manga, Black Zetsu only uses katakana for okurigana and furigana. This is often conveyed in the anime through a deeper voice. While he sometimes has a difference of opinions with White Zetsu, the two halves are still able to function as a single entity.

Zetsu is extremely trustworthy, obedient and loyal, being entrusted with Akatsuki's secrets and knowledge of Madara's Eye of the Moon Plan. Because of his ties to Madara, Zetsu has been working with Obito for a long time, originally helping Obito find and convince Nagato to join them. Unlike White Zetsu, who was kind to his allies, Black Zetsu saw anyone beneath Madara as useless. When Obito lost the tailed beasts, Black Zetsu commented on how he was a more effective servant to Madara. He also had no qualms about using Obito's dying body as a host when he fought Kakashi and Minato, showing just how little he cared about the Uchiha's well-being, while deriding on Obito for being useless for his treason.

Zetsu's main role within Akatsuki is to function as a spy with other duties that were similar to those of a hunter-nin. He is also able to control his body and take part in the tailed beast sealing ritual simultaneously, which, in addition to being unique to him, allows him to act as a lookout while the sealing takes place. When an agent of Akatsuki, or possibly even a member, dies, Zetsu is sent to devour their bodies so as to not have their secrets revealed, which further adds to his nature as a half-plant creature. Zetsu is also the one sent to retrieve the rings of dead Akatsuki members. Due to the role he plays, Zetsu is the only member of Akatsuki to act without a partner on a regular basis. As such, he operated on his own, often moving between the different locations where the other Akatsuki members were located. This resulted in other members often reporting directly to him, rather than the figurehead leader, Pain. Zetsu would in turn report directly to Pain along with Obito, who took full control over the organisation after Nagato's death and treachery.

Appearance
When together, the two Zetsus are easily distinguished by the two large venus fly-trap like extensions that envelop his head and upper body, giving him a plant-like appearance. When his extensions are open and his head is visible, it is revealed that Zetsu has short green hair, yellow eyes, and that his body has two different coloured halves. His left side is completely white, while the right side is almost entirely black. The black colour does not cover his black half's entire body, as it only extends partially down his leg, which was originally his white half's right leg. Under his Akatsuki cloak, Zetsu wears blue pants and sandals. He also has both legs wrapped in bandages, which hide the area where his right leg's black colouring merges with his white foot.

Unlike White Zetsu, who possesses human-like facial features and a proper eye, Black Zetsu shows no visible orifices at all and only his iris is visible. Black Zetsu also has white dots along the edges of his body where the two halves meet; these are not flat markings, but rather protrude from his body, like little white bumps. In the anime, his fingernails are painted pink and his toenails, as seen at his début, are blue. He also wears his green Akatsuki ring, which bears the kanji for, on his right little finger.

When the two halves split apart, the plant-like extensions split and hang from the waists of both. Their clothes also split in half along with them, leaving each with one pant leg or half of an Akatsuki mantle, although the two halves later discard their torn clothing. When they are emerging from the ground while split, their plant-like extensions surround the two halves in a circular pattern. The two have also demonstrated the ability to grow an additional leg to substitute for their missing half when split. After escaping capture by Chōjūrō and reshaping the black matter in his lower body into a new upper body, Black Zetsu no longer has hair.

Abilities
Zetsu, as a whole, has yet to be seen in battle. The technique he has been shown using the most is Mayfly, which allows him to merge with the ground to quickly travel to a new location, though he isn't as fast as Obito's space–time travelling. This technique is ideal for Zetsu's function as a spy, as it erases his presence as well, and is an ability that both halves, as well as White Zetsu's clones, can use. In the anime, this technique allowed a White Zetsu Army clone to bury Deidara's underground mines. In addition to functioning as a single entity by communicating through their thoughts, Zetsu's two halves are able to split apart, which allows them to act independently. While separated, the two halves can extend roots underground to communicate with each other over long distances.

Black Zetsu has demonstrated the ability to "record" the things he sees, as he has stated that he recorded the battles between Sasuke and Itachi, and between Kisame and Killer B. He is also capable of showing these "recordings" through unknown means. Black Zetsu is also a very powerful sensor, as he was able to sense Naruto Uzumaki and Killer B as soon as they touched the ground upon leaving the Island Turtle, which was some distance away. As a manifestation of Madara's will, Black Zetsu is able to telepathically communicate with Madara. Upon being bisected and immobilised, Black Zetsu separated from the white portion of his body by seeping the black matter in his lower half into the ground and subsequently forming it into a new upper body. This new body was then able to meld with and control a weakened Obito's body, forcing him to perform the Outer Path: Samsara of Heavenly Life Technique, as well as keeping him alive while melded, as otherwise Obito would have died as a result of using the technique.

Nature Transformation
Because of his origin, Zetsu's genetic material is nearly identical to that of Hashirama Senju's, as seen from Shizune and Sakura Haruno's autopsy of one of the White Zetsu clones. Because of this, Zetsu is capable of using Hashirama's Wood Release, albeit on a much weaker scale. This has been most prominently demonstrated through Black Zetsu, who has been depicted transforming parts of his body into roots for offensive purposes during battle.

Sasuke Retrieval Arc
After Sasuke and Naruto's fight at the Valley of the End, Kakashi and Pakkun appear to bring Naruto back home. As the three begin the journey back home to Konoha, Zetsu appears from the ground, having witnessed the whole battle. Later his silhouette appeared with the rest of the Akatsuki members where they discussed Orochimaru taking Sasuke Uchiha, the capturing of the Nine-Tails and the furthering of their plans.

Kazekage Rescue Arc
During the extraction of the One-Tail, Zetsu is told by the Akatsuki Leader to use his real body to use as a lookout, in which he identifies several enemies such as Team Guy, Team Kakashi, as well as Chiyo who was with the latter. Later, he is sent to dispose the corpses of Mukade and Yura, finding Mukade a delicious meal.

After Sasori and Deidara were defeated, Zetsu and Tobi were sent to retrieve their rings, and dispose of their corpses. However, he was unable to eat Sasori due to him being a puppet, but was amazed to finally see what the real Sasori looked like. Tobi found Sasori's ring, wishing to take his place. Black Zetsu thought this was a bad idea, but White Zetsu thought otherwise, noting that Tobi was a good person. They later found Deidara's severed right arm and believe him dead until he arrived and proved them wrong. This caused Black Zetsu to wonder why Deidara hadn't captured Naruto Uzumaki, to which Deidara replied that he had already fulfilled his quota either way.

Hidan and Kakuzu Arc
After Hidan and Kakuzu defeated Yugito Nii, Zetsu appeared to retrieve Yugito, and asked if Hidan was finished with his long winded ritual. When Hidan claimed that they were infidels ignorant of prayers, Zetsu told him that when sad and alone, all one can count on is yourself. Kakuzu, disagreeing stated that money was all one could count on. White Zetsu agreed that money was important, however Black Zetsu stated finding the next one was much more important. Zetsu is later seen sealing the Two-Tails.

Itachi Pursuit Arc
After Deidara's death Zetsu was sent to recover his body, with White Zetsu wondering what happened to Tobi. Black Zetsu mentioned that based on the damaged area, he was most likely caught up in Deidara's explosion. Later, when Pain had encouraged the organization to mourn Deidara's loss, White Zetsu took it on himself to mourn for Tobi's loss, while Black Zetsu thought such a notion was ridiculous. After Pain's fight with Jiraiya, Zetsu revealed himself to have been watching the whole battle. As Pain announced he was going to capture the Nine-Tails, White Zetsu said it would be an interesting battle and wanted to go. However Black Zetsu had another battle in mind, and they decided to watch Sasuke's battle with Itachi. Both halves spectated and commenting on the battle, with Black Zetsu offering knowledge on various Sharingan abilities. When Itachi died, Zetsu noted that Itachi shouldn't of been that weak, believing him to have already been afflicted prior to the battle. He later appeared near Tobi while he was engaged in combat with the Eight Man Squad, to report to him the result of the fight and was called "aloe vera" by Naruto, who angrily demanded him to reveal Sasuke's location. White Zetsu took offence to the name, while Black Zetsu told him to ignore him. They then led Tobi to where Itachi and Sasuke were, with Black Zetsu confirming to Tobi that he had indeed recorded the fight. After a meeting with Taka and Kisame, Tobi met with Zetsu on a bridge where they discussed the fact that Itachi — who had been hampering their plans — was dead and Zetsu lamented on the fact that so many Akatsuki members had died. Tobi said that they encountered problems along the way, but acknowledged that they couldn't get as far as they did without them, but most importantly Sasuke was in his hands now.

Invasion of Pain Arc
In the anime, Zetsu was present alongside the other Akatsuki members when they extracted the Six-Tails from Utakata. Zetsu is present when Akatsuki begins sealing the Eight-Tails, and when it is revealed that the jinchūriki fooled Sasuke and replaced himself with a tentacle, White Zetsu flew into a hysterical laughter, which greatly annoyed Black Zetsu. Upon Nagato's death and Naruto returning to the village crowned as a hero, Zetsu revealed himself to have hidden inside a tree, watching the entire fight between them, hardly believing Pain to have been defeated, but decided to relay the information to Tobi. He then returns to Tobi and Kisame, reporting Nagato's death and betrayal, also mentioning that Konan wouldn't be returning either.

Five Kage Summit Arc
Zetsu finds Tobi after the later had encountered Taka, revealing that Konoha had already been destroyed, and that Danzō had been named the acting Sixth Hokage. He then mentioned to Sasuke that naruto had defeated Pain, and was probably stronger than him. When Taka agreed to go to the Kage Summit, Zetsu revealed his ability to split in half, and White Zetsu proceeded to lead Sasuke and his team to the Kage Summit while Black Zetsu remained behind and discussed with Tobi the fact that they might lose control over Sasuke and would therefore lose their last chance to have someone sync with the Demonic Statue of the Outer Path. Tobi declared that he was tired of hiding, and explained that they needed to speed up the "Eye of the Moon Plan".

White Zetsu and Black Zetsu meet up at the site of Killer B and Kisame's battle only to reveal that Kisame's decapitated body was actually one of White Zetsu's shape-shifting clones. It is then revealed that Kisame, by having the clone fake his death, was then able to infiltrate Kumogakure while inside Samehada which was being carried back to Kumogakure by Killer B who intended to use it as his own weapon. Black Zetsu then stated that it was their feeding time and that they should merge once again.

Confining the Jinchūriki Arc
In the anime, Zetsu sees off Tobi before he made his journey to Amegakure to retrieve Nagato's Rinnegan, and upon Tobi's acquisition of the Rinnegan, Zetsu informed him that the scroll with the information that Kisame Hoshigaki sent through his messenger shark had arrived, also noting that everything seemed to be going in their favour. Kabuto mentioned that he could make Zetsu stronger and that he was the key to fighting the shinobi forces, with Zetsu being shocked and wondered just how much Kabuto knew about them and their plans, questioning if Tobi should really trust him. Later, Tobi promised to give him "one Zetsu" if Kabuto captured the Nine-Tails, and Zetsu joined them as Tobi revealed his army comprised of one hundred thousand clones of White Zetsu to Kabuto, which he would use to fight the numbers of the Allied Shinobi Forces.

Shinobi World War Arc
Supervising Sasuke's recovery, Zetsu told him to be patient when asked if his bandages could be removed, remarking that when he did regain his sight it would be to a different world. As the Fourth Shinobi World War commenced, Black Zetsu departed to enact Tobi's plan to capture the daimyō and hold them hostage to force the opposition to bring Naruto and Killer B to them. Later, after Kabuto demonstrated the Summoning: Impure World Reincarnation technique, Black Zetsu emerged from the ground near Tobi. When asked if White Zetsu's spores had been placed on Kabuto's body, Black Zetsu confirmed, before being instructed to carry out his assigned tasks.

Emerging from the ground near the daimyō's hideout, Black Zetsu infiltrated the structure, despite alerting the enemy to his presence. However, upon discovering the daimyō's absence, Black Zetsu retreated and declared that they shouldn't underestimate his capabilities, as he was a part of the very land itself. Later locating his desired targets, he was instead obstructed by Mei Terumī and her squad, but sensing the Eight and Nine-Tails' chakra while confronting the team, he immediately communicated this to Tobi via White Zetsu. Told that the daimyō were no longer necessary with their quarry now in the open, Black Zetsu was ordered to continue with his guerilla tactics against the Mizukage's team to keep them from regrouping with the rest of their forces. The fight continued throughout the night.

Continuing to battle with Mei and her squad, Black Zetsu observed the arrival of Naruto's shadow clone to their location, who then proceeded to crash into a tree beside him. Growing roots from portions of his body whilst fighting, he used them to trip Naruto and avoid his Rasenshuriken, only to be bisected from behind by the enlarged blade of Chōjūrō's Hiramekarei. Immobilised, Black Zetsu wondered how the sword grew to such a size in an instant and was then sliced in half and pinned to the ground by Chōjūrō's blade as the Mizukage departed. Having been reincarnated, Madara telepathically communicates with Black Zetsu, ordering him to keep watch on Obito until after his "playing" with the Five Kage is done. Subsequently, Black Zetsu seeps into the ground, escaping.

Return of Madara Arc
With Obito weakened after the tailed beasts were extracted from him, Madara enacted his trump card. With this, Black Zetsu suddenly emerged from underground and restrained him. As he began to meld with half of Obito's body, Madara was able to force Obito into using the Outer Path: Samsara of Heavenly Life Technique. Apologising as this all unfolded, Black Zetsu noted that from the start, this was his sole purpose for existing. With Madara's revival a success, Black Zetsu attempts to retrieve Madara's Rinnegan eye from Obito until Minato and Kakashi intervene. Black Zetsu once more melds with Obito's body, using the Uchiha's body to battle his former team and noting that his merger was the only thing keeping Obito alive. While both sides were at a stalemate, the Demonic Statue of the Outer Path emerged from Obito's artificial body, quickly being teleported. Afterwards, Black Zetsu again attempted to take the left Rinnegan. Obito, managing to resist Black Zetsu's control of his hand, told Kakashi to destroy the Rinnegan. Black Zetsu, realising what the summoning of the Demonic Statue meant, informed his enemies that Madara has regained his right Rinnegan.

Standing to face Minato and Kakashi in battle, Zetsu complained about the duo's stubbornness before Gaara arrived along with Sakura and a dying Naruto to their location. Black Zetsu managed to steal Kurama's Yin half when Minato tried to transfer it into his son, thus becoming its jinchūriki. Soon afterwards, Zetsu was joined by Madara who complained about having to come all the way there.

Naruto 6: Road to Ninja
Zetsu was responsible for sending several clones disguised as deceased Akatsuki members to attack Konoha at the beginning of the movie. Later, he was seen with Tobi after Naruto and Sakura returned to their world, noting that they were so close to capturing the Nine-Tails.

Creation and Conception
In Naruto Hiden: Sha no Sho Character Official Data Book, Kishimoto revealed that he had originally planned for Akatsuki to be a group of monsters, "with almost no human characteristics", and that Zetsu's design was modelled after an insectivorous plant. He also stated that he had decided to make Zetsu half black and half white to "better show his split personality".

Trivia

 * According to the databook:
 * Zetsu's hobby is observing unique shinobi.
 * Zetsu wishes to fight people who are likely to leave behind a corpse that will make a good meal.
 * Zetsu's favourite food is "chewy" people, while his least favourites are konnyaku and jelly.
 * Zetsu's favourite phrase is, which roughly means "The only one you can count on is yourself".
 * Wherever Tobi is, Zetsu is never far behind.
 * Tobi made a deal with Kabuto, in that he would give him "one Zetsu", provided he were to capture the Nine-Tails.
 * Zetsu and the White Zetsu Army clones are not dissimilar to the legends told of the mandrake plant used to create artificial men.
 * Zetsu is the only member of Akatsuki that has yet to make a playable appearance in any Naruto video game.

Quotes

 * (To Tobi about joining Akatsuki) Black Zetsu: "Idiot, it's not that simple." White Zetsu: "It'll be all right, after all, Tobi is a good boy."
 * (To Hidan) White Zetsu: "When your sad and alone…" Black Zetsu: "…The only one you can count on is yourself."
 * (To White Zetsu) Black Zetsu: "A weapon's strength or weakness is dependent on the users ability to use it. An expert with a pebble can still beat a novice with a shuriken."
 * (To Sasuke) Black Zetsu: "Not yet. Be patient." White Zetsu: "The next time you open your eyes you'll be seeing a whole new world… things are getting really fun!"
 * (To Minato and Kakashi) Black Zetsu: "I'm Madara's will. I'll eliminate whoever stands in his way. You and Obito took Madara way too lightly, and you underestimated me as well."