Witch-Maw Elemental

Trample, Deathtouch
Witch-Maw Elemental's power and toughness are
equal to the number of cards in exile.
When Witch-Maw Elemental enters the battlefield, mill the top half of your library,
rounded up.
You may cast witch-Maw Elemental from exile.
In Witch-Maw, there is only hunger.