At the beginning of each end step, put a slime counter on each creature you don't control. Creatures you don't control get -1/-1 for each slime counter on them. Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token. {U}{B}, Sacrifice a Slug: Draw a card.

Whenever this creature enters or attacks, put a slime counter on up to one other target creature. Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.