Minazuki

Minazuki is the manifested spirit of Retsu Unohana's Zanpakutō that is seen during the anime-exclusive Zanpakutō Rebellion. Minazuki's spirit takes the form of a slim humanoid figure covered in bandages and wearing a very long light green hood (resembling the look of the released Shikai form). Due to its bandages, it is unknown whether it is male or female. (Source: Bleach Wiki)