Korosensei

Korosensei (殺せんせー, Korosensei) is a teacher for class 3-E of Kunugigaoka Junior High School and the main antihero of Ansatsu Kyōshitsu. He was responsible for carving out a large chunk of the moon to become a permanent crescent moon and plans to destroy the earth after teaching class 3-E for a year.

Appearance
Korosensei has the appearance of a squid, he is quite tall, he has a large bulb head with a large smile and tiny beady eyes. He uses two tentacles, as arms, with two fingers and use the rest to walk with them. He wears a black academic dress, a small black square academic cap with a yellow tessel, a black tie with a yellow crescent-shaped moon on it.

The color of his face varies based on his mood. His face is black when he is extremely angry. When he is neutral, his face is yellow. When a student of his gets an answer wrong, he has an X over his face, and when a student gets a question right, he has a circle over his face. He wears a graduation uniform, and has eight tentacles.