Consumeslug, Spawn of Toxrill

At the beginning of each end step, put X slime counters on each creature you don't control,
where X is the number of slugs you control.
Creatures you don't control get -1/-1 for each
slime counter on them.
Whenever a creature you don't control with one
or more slime counters on it dies, create that
many 1/1 black Slug creature tokens.
{b}{g}, Sacrifice X Slugs: Draw X cards.