Koro's Forms from Ansatsu Kyoushitsu HD Wallpaper

This illustration displays various forms and expressions of Koro-sensei, a yellow, octopus-like character wearing a graduation cap. The forms include 'normal', 'nameteru', 'mistake', 'right', 'sad', 'shock', 'nemui', 'angry', 'anger', 'osinobi', 'takotubo', 'poison1', 'poison2', 'poison3', and 'new stage'. Each form has a distinct color and facial expression.