Foul-Tongue Invocation (DTK) from Dragons of Tarkir, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Daarken
• Card Text:
  As an additional cost to cast Foul-Tongue Invocation, you may reveal a Dragon card from your hand.
  Target player sacrifices a creature. If you revealed a Dragon card or controlled a Dragon as you cast Foul-Tongue Invocation, you gain 4 life.