Stormbreath Dragon (THS) from Theros, available at 401 Games Canada.

• Rarity: Mythic Rare
• Finish: Normal
• Artist: Slawomir Maniak
• Card Text:
  Flying, haste, protection from white
  5RR: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
  When Stormbreath Dragon becomes monstrous, it deals damage to each opponent equal to the number of cards in that player's hand.