Devourer of Worlds

Deathtouch, Hexproof, Trample
When Galactus enters the battlefield, all players discard {2} lands.
Devour {x} (When this creature enters the battlefield, sacrifice {x} creatures or land. This permanent enters the battlefield with {x} +1/+1 counters on it for each creature/land sacrificed this way.)
Annihilator {2} (Whenever this creature attacks, defending player sacrifices {2} creatures.)
"I hunger."