Primordial Hydra [Magic 2013]

Set: Magic 2013 Type: Creature — Hydra Rarity: Mythic Cost: {X}{G}{G} Primordial Hydra enters the battlefield with X +1/+1 counters on it.At the beginning of your upkeep, double the number of +1/+1 counters on Primordial Hydra.Primordial Hydra has trample as long as it has ten or more +1/+1 counters on it.