Tobi (Zetsu)

This Zetsu clone is a subordinate of Madara Uchiha and was assigned to aid Obito Uchiha alongside White Zetsu during the young Uchiha's rehabilitation.

Background
He was one of many Zetsu clones created using the Demonic Statue of the Outer Path and Hashirama's living clone. Serving as one of Madara Uchiha's loyal minions and spies, he met and befriended Obito shortly after the latter was saved by Madara being designated the task of making sure the young Uchiha was of use to Madara when he woke up. He, along with White Zetsu, enjoyed annoying and teasing Obito about things such as what he murmured in his sleep and bodily functions. Over time, the duo became friends with the young Uchiha.

Months into Obito's rehabilitation, White Zetsu returned to the underground base and urgently alerted Obito that he saw Kakashi and Rin being cornered by Kirigakure shinobi while he was outside. Resolved to save his friends, Obito tried to break the huge stone blocking the exit in an effort to escape, but destroyed his artificial arm, only cracking the wall in the process. Seeing how desperate Obito was, the swirl-patterned Zetsu noted that his limbs were not strong enough to break through stone yet, and offered himself as a suit of sorts for Obito to wear in order to make it to the surface. Although Obito was sceptical about whether they had permission to help, White Zetsu noted that it would be fine.

Personality
When first meeting Obito, "Swirl" Zetsu was playful and enjoyed teasing him about things such as what he murmured in his sleep. He was also very curious about bodily functions as they had no need for them. Although Obito was initially hostile, the two befriended each other during the former's rehabilitation. He believes that the Eye of the Moon Plan is good for mankind, and sees Madara as a benevolent man. He is also kind-hearted, as shown when he and White Zetsu decide to help Obito without Madara's permission. Strangely, he is interested in what it is like being able to defecate since he cannot do so himself.

Appearance
"Swirl" Zetsu is easily distinguished by the swirl-pattern of his face that only shows the hole in the place of his right eye. Though it has a swirl pattern running from his head down to his waist. These swirls are shown to be able to open in a similar manner to the fly-trap extensions of the current Zetsu. This Zetsu shows no visible orifices at all, but has a fully defined body.

Abilities
As a Zetsu clone, "Swirl" Zetsu is presumed to have the standard abilities they normally possessed. "Swirl" Zetsu and White Zetsu also claim to have a vocabulary and brain that surpasses that of a human's. Being an artificial human created from Hashirama's cells, he can survive without food or water and needs to carry out no normal bodily functions.

Later "Swirl" Zetsu displays the ability to open up his top half entirely, and use himself as a suit of sorts to encase someone in.

Trivia

 * Swirl Zetsu holds many similarities to the "Tobi" alias that Obito used during his time in the Akatsuki. His "face" closely resembles the mask that Obito wore until the start of the war, and his personality is identical to the Tobi persona.