野生林の災い魔 (Wildwood Scourge) (ja)
Creature - Hydra
(CMC 1)
Wildwood Scourge enters the battlefield with X +1/+1 counters on it.
Whenever one or more +1/+1 counters are put on another non-Hydra creature you control, put a +1/+1 counter on Wildwood Scourge.