Bucky "Chicken Devil"

Bucky is the Chicken Devil, a devil that embodies the fear of chickens. Tanaka presented Bucky as a class pet, telling the students that in 3 months they'd have to kill him. Over this time he became a beloved pet to the class and they refused to kill him, even if hes a devil, to which Tanaka was elated, saying the real lesson was to value all life. (Source: Chainsaw Man Wiki)