Kolkovian Hydra

Kolkovian Hydra enters the battlefield with X +1/+1 counters on it.
When Kolkovian Hydra dies, create a 1/1 green snake creature token with deathtouch and, "Sacrifice 4 snakes: return a card named Kolkovian Hydra from your graveyard to your hand," for each +1/+1 counter on Kolkovian Hydra.