Cthulhu, Risen from the Deep

Cthulhu, Risen from the Deep, costs {x} less to
cast, where X is the total number of creatures in
your graveyard.
Fear, trample, islandwalk
When Cthulhu, Risen from the Deep attacks, defending player mills two cards, then if that
player has twenty or more cards in his or her graveyard, that player loses the game.