Emrakul's Carnage Maw

Menace, Trample
Emerge {6}{b}{b}{r}{r} (You may cast this spell by sacrificing a creature and paying the emerge cost
reduced by that creature's converted mana cost.)
When you cast this spell, target opponent exiles
the top four cards of their library, then you may
put any number of land cards that player owns
from exile onto the battlefield under your control.