Shub-Niggurath

When Shub-Niggurath enters the battlefield,
each player puts the top X cards of his or her
library into their graveyard, where X is the
amount of mana spent to cast it.
{t} Return target creature from a graveyard
into play under your control. If it would
leave the battlefield, exile it instead.
Ia! Shub-Niggurath! The black Goat of the Woods
with a Thousand Young!