Arsenic
33
As
Arsenius
This metalloid is highly poisonous to almost all lifeforms, except for a few bacteria. The Poison of Kings and the King of Poisons has been known and used since ancient times, for example as a green pigment in wallpaper. Nowadays it’s found in semi-conductors and insecticides.
Arsenius the adulterator would love to be a bartender. Only his fellow monsters don’t trust his mixing skills.