The Megasaur Colossus

Trample, Haste
When The Megasaur Colossus attacks, sacrifice a land or sacrifice The Megasaur Colossus. If you sacrifice land this way, you get {e}{e}{e} (three energy counters).
Pay {e}{e}{e}{e}{e}{e}{e}{e}{e}{e}{e}{e}{e}{e}{e} (fifteen energy counters): The Megasaur Colossus gets +X/+X until end of turn where X is its power.