Assemble the Rank and Vile (Conspiracy: Take the Crown)

Conspiracy - Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.)
Creatures you control with the chosen name have "When this creature dies, you may pay {B}. If you do, create a tapped 2/2 black Zombie creature token."