Ulamog, the Infinite Gyre

When you cast Ulamog, the Infinite Gyre, destroy
target permanent.

Annihilator 4 (Whenever this creature attacks,
defending player sacrifices four permanents.)

Ulamog is indestructible.

When Ulamog is put into graveyard from anywhere,
its owner shuffles his or her graveyard into his or her library.