Pernicious, Plague Corrupter

Whenever another nontoken creature dies,
put a Plague counter on target creature.
Whenever another target nontoken creature
with a Plague counter on it dies, create X 1/1
Black Zombie creature tokens with Decayed,
Infect and Deathtouch, where X is the
number of Plague counters that was on
target creature. Activate this only once per turn.