Fungal Artillery

Position 3 or 4 — {t}: Mark target creature. (Marked targets can be attacked by creatures with Marked Attack)
Whenever Fungal Artillery blocks a creature, put a blight counter on it. (It has, "At the beginning of your upkeep put a -1/-1 counter on this creature for each blight counter, then lose 1 life.)
"Confusion, nerves, and panic!"
— the Ancestor