Ulamog, the Infinite Gyre

Ulamog, the Infinite Gyre {11}

Legendary Creature - Eldrazi | Power/Toughness: 10 / 10
When you cast this spell, destroy target permanent.
Indestructible
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents.)
When Ulamog, the Infinite Gyre is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.