Tobi

Height: 175 cm – 182 cm

Tobi was formerly Zetsu's subordinate.

He became a full Akatsuki member after Sasori's death.

While his physical appearance remains a mystery, Zetsu has implied that he is relatively young when one side of him referred to Tobi as a "good boy." He respects Deidara, referring to him as Deidara-senpai. Tobi's personality is rather odd in comparison with other Akatsuki members. While most of the members are dedicated and serious, though somewhat argumentative or even hostile towards each other when not fighting, Tobi is more carefree and goofy. His personality does not please Deidara, who believes that all Akatsuki members should be serious and calm. Tobi unintentionally irritates Deidara frequently, which usually results in Deidara attacking Tobi in a comedic fashion.

In chapter 599:

It is revealed that Tobi is actually Obito Uchiha, who was teammates with Kakashi Hatake and Rin under the Fourth Hokage. Obito got his right side crushed when he saved Kakashi by pushing him out of the way of a rock slide. Unable to escape with his teammates, Obito had Rin implant his remaining Sharingan eye in Kakashi's damaged eye socket as a gift. After that it was believed that Obito died.