Bioweapon

All nongerm and nonartifact creatures get -1/-1 for each germ creature on the battlefield.
Create an X/X black and green horror creature token, where X is the number of creatures killed this way.
"Sometime long ago our experiments outpaced our ability to contain them. A tragedy yes, but one that yielded significant data."
— Salvador Le Doux, Dean of the Iconoclasts