Skulking Cyst

When Skulking Cyst enters the graveyard
due to combat damage place a -2/-2 counter
on a creature who did combat damage to Skulking Cyst this turn.
Though often cloaked in the detritus of a previous victim, the skulking cyst's true "heart"
is a 1-foot diameter spherical sac that contains fluid and semisolid necrotic flesh, which slowly undulates as if in a mockery of breath.