Poisoned Blood

When Poisoned Blood enters the battlefield,
create a Poison token (it is an artifact with
"{1}, {t}, sacrifice this artifact: put a -1/-1 counter on
target creature").
Whenever you sacrifice a Poison, you may pay {1}. If you do, create a Blood token.
{1}, {t}, Sacrifice Poisoned Blood: put a -1/-1
counter on target creature.