Shadow of the Beast

As an additional cost to cast Shadow of the Beast, reveal a creature card from your hand.
Target creature gets +X/+Y until end of turn, where X is the revealed card's power and Y is its toughness.
"My platoon and I were travelling through the forests of Archa. A sudden darkness fell over us and we looked up, eager to find the cause of the problem. We did not have to search for long."