Predators' Hour (VOC) from Crimson Vow Commander, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Tomas Duchek
• Card Text:
  Until end of turn, creatures you control gain menace and "When this creature deals combat damage to a player, exile the top card of that player's library face down. You may look at and play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell."