zombie appocolypse

When this card enters the battlefield, create a 1/1 black zombie creature token with "this creature can't block"

{t}, tap a zombie you control: create a 1/1 black zombie creature token with "this creature can't block"

whenever a creature enters the graveyard, if it was dealt damage by a zombie this turn, create a 1/1 black zombie creature token with "this creature can't block"