Apocalypse Hydra
Conflux — mythic
Creature — Hydra
Apocalypse Hydra rulings:
2009-02-01: For example, if X is 4, Apocalypse Hydra enters the battlefield with four +1/+1 counters on it, but if X is 5, it enters the battlefield with ten +1/+1 counters on it.
2009-02-01: The first ability checks the number you chose for X, not the amount of mana you actually spent.