Work in Progress

Contagious (Whenever this creature blocks or
becomes blocked by a creature, if that creature doesn't
have Contagious, it gains Contagious.)
Creatures you control with contagious have
wither.
Whenever a nontoken creature with a -1/-1
counter on it dies, exile that creature. If a
creature was exiled this way, create a 2/2 black
Zombie creature token with Contagious.