Toxic Dragon

Flying Toxic 2
At the beginning of each end step,
put a toxic counter on each creature
you don't control.
Creatures you don't control get -1/-1
for each toxic counter on them.
Whenever a creature you don't
control with a toxic counter on it
dies, create a 1/1 Black Green Toxic Dragon
creature token.
{b/g}{b/g}, Sacrifice a Dragon token: Draw a card.