Koro-sensei
About
His name comes from Korosenai (殺せない) means "cannot be killed" and sensei, means teacher. Literally, his name means unkillable teacher.
Koro-sensei is made up of anti-matter. He will inevitably die in March, whether the students assassinate him or not.
It is later revealed that the chance of this happening was less than 1%.
Koro-sensei was previously known as the "God of Death."
Koro-sensei did not actually destroy the moon, a rat infused with anti-matter did.
