Crulik, Ulamog's Progeny

Annihilator 3 (Whenever this creature attacks, defending player sacrifices three permanents.)
When Crulik, Ulamog's Progeny enters the battlefield, you may search your library for either Ulamog, the Ceaseless Hunger or Ulamog, the Infinite Gyre, reveal it and put it into your hand. Then shuffle your library.