Susanoo is not a standalone character in Naruto, but a powerful chakra manifestation used by certain Uchiha who have awakened the Mangekyō Sharingan. It appears as a giant humanoid avatar made of chakra that surrounds and protects the user, while also serving as a devastating offensive weapon. In the series, Susanoo is associated with elite Uchiha abilities and is used in major battles by characters such as Itachi, Sasuke, and Madara. It represents overwhelming power, defense, and the peak of Sharingan combat techniques.