Silhouette: Koro-Sensei

Koro-Sensei is the ex-assassin, yellow tentacle monster teacher of Kunugigaoka Junior High School’s 3-E class. He is capable of moving and flying at Mach 20 speed, can instantaneously regenerate his body and is invulnerable to any regular form of attacks. With all of this, you would think him impossible to kill but that is exactly what the class of 3-E has been instructed to do and it is Koro-Sensei’s task to train them to do so.