Cephalid Coliseum (ODY) from Odyssey, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: John Avon
• Card Text:
  T: Add U to your mana pool. Cephalid Coliseum deals 1 damage to you.
  Threshold — U, T, Sacrifice Cephalid Coliseum: Target player draws three cards, then discards three cards from his or her hand. (Play this ability only if seven or more cards are in your graveyard.)