Hauntwoods Shrieker (Duskmourn: House of Horror 349) - Mythic Magic: The Gathering Card

Whenever this creature attacks, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)
: Reveal target face-down permanent. If it's a creature card, you may turn it face up.