Centurion Hydra

Lifelink, indestructible
Centurion Hydra enters the battlefield with a
+1/+1 counter on it for each creature in your
graveyard.
—Whenever you gain life, put that many +1/+1 counters on Centurion Hydra.
—Whenever Centurion Hydra takes damage.
Remove that many counters from it and lose that
much life.