Tobi (Zetsu)

"I told you getting past me will not be easy… Which reminds me… My question still remains unanswered... I asked what does it feel like to poo…? Well… I'm thinking it's the refreshing feeling you get after killing someone."

- Tobi speaking with the Shinobi Alliance.

Tobi, also known as Guruguru, is a minor antagonist from the manga/anime series, Naruto. He is one of the many humans that fell victim to Kaguya's Infinite Tsukuyomi in the past and was transformed into a White Zetsu. Unlike the other Zetsu, Tobi is very unique in the sense that he has a spiral pattern across his entire body.

He is voiced by Nobuo Tobita in the Japanese dub of the anime, while he is voiced by Travis Willingham in the English dub.

Personality
Tobi used to be a cheerful and playful being when first meeting Obito, as he would often spend his time having fun teasing with him. Despite this, he was a good friend to him and would aid him whenever Obito needed help for his missions. Tobi was also curious regarding how the human body worked and asked various questions, some involving feces.

By the time of the Fourth Shinobi World War, Tobi became a more serious individual, but still was curious on how the human body worked. Most of his mannerism was used by Obito when he was in the Akatsuki under his Tobi guise.

Background
Tobi was originally one of the various humans transformed into a White Zetsu after Kaguya had originally released her Infinite Tsukuyomi. He and the other White Zetsu were sealed away within the Demonic Statue of the Outer Path and were kept in there for years, until Madara Uchiha came across the statue and released them by creating a tree with Hashirama's DNA. As a result, he and the other White Zetsu were modified by Hashirama's DNA, leading Madara to believe he, along with Black Zetsu, were an extension of his will.

When Madara rescued Obito and treated his injuries, Tobi and one particular White Zetsu accompanied the young boy and befriended him. Obito at first was displeased with them, but over time learned to grow fond of him and even gave Tobi the nickname Guruguru, describing his spiral appearance.

As time went on, White Zetsu had alerted Obito about Kakashi Hatake and Rin Nohara, regarding their encounter with the Kirigakure shinobi. Tobi accompanied and aided Obito by helping him escape the area Madara was keeping him and the two headed out to help them. When Obito arrived to the scene, however, he found Rin killed at the hands of Kakashi. Enraged, Obito used Tobi's Wood Release and went on a rampage slaughtering all of the Kirigakure shinobi around him.

Following the events, Obito would return back to Madara and agree to help him accomplish the Eye of the Moon Plan. Tobi would continue to play his role on aiding Obito, following Madara's initial passing.

Fourth Shinobi World War
Tobi took part in the Fourth Shinobi World War, in which he was in possession of Yamato's body and faced off against the Shinobi Alliance, in order to buy Madara time for him to become the Ten-Tailed Beast's Jinchuriki. Tobi later encountered Orochimaru and the rest of Taka, who attempt to save Sasuke Uchiha. Tobi dispatches Karin, but is caught off by guard by Suigetsu Hōzuki then later infected with a Curse Mark by Orochimaru. Despite their efforts, Tobi shrugged the infection and let them off for the time being.

Once the Infinite Tsukuyomi was unleashed, Tobi released Yamato, no longer needing his body. However, once the genjutsu was dispelled by Naruto and Sasuke, Tobi and the other Zetsu disintegrated.

Body Structure
Tobi was not that different compared to other White Zetsu. Like his companion, White Zetsu, Tobi was a being made of nothing but a white flesh kind of material. As such, he did not need any sort of substance to function and survive, such as food and water. His body was hollow, however and because of that, he could open up like a cocoon and wrap himself around others. This ability of his provided good use to people such as Obito as it supplied them enhanced strength, durability and access to his ninjutsu.

Wood Release
Like many of the other White Zetsu, Tobi had access to the Kekkei Genkai, Wood Release, due to his DNA being nearly identical to Hashirama's. While likely nowhere near as powerful as Hashirama's usage with this ninjutsu, Tobi has shown competent use of it when bonded with Obito, though in Obito's case, his Wood Release was used out of pure rage. When bonded with Yamato, Tobi was able to create the Kanzeon Lotus King, a technique similar to Hashirama's Sage Art Wood Release: True Several Thousand Hands. Despite his connection to Hashirama, he could not use senjutsu, however.

While he did not have access to Hashirama's sage arts, Tobi could still make use of all five elemental nature releases, via utilizing the Kanzeon Lotus King.

Trivia

 * Tobi's nickname, Guruguru, translates to "Swirly" in English, which describes his spiral pattern around his body.
 * Obito's orange mask was modelled in the likeness of Tobi himself.