Terrifying Trap Hole Nightmare

Destroy target creature an opponent controls. Then you may exile X cards from your graveyard, where X is the mana value of that creature. If you do, return that creature
from that player's graveyard to the battlefield under your control.
Trap {3}{b}{g} (During your turn, you may
pay {2} and exile this card from your hand face down. Cast it on a later turn for its trap cost.)