Phyrexian Dragon Engine (BRO) from The Brothers' War, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Chris Rahn
• Card Text:
  Double strike
  When Phyrexian Dragon Engine enters the battlefield from your graveyard, you may discard your hand. If you do, draw three cards.
  Unearth 3RR
  -------------
  Meld Partner: Mishra, Claimed by Gix
  When Melded, it becomes the following:
  Mishra, Lost to Phyrexia
  Legendary Artifact Creature — Phyrexian Artificer
  Whenever Mishra, Lost to Phyrexia enters the battlefield or attacks, choose three —
  • Target opponent discards two cards.
  • Mishra deals 3 damage to any target.
  • Destroy target artifact or planeswalker.
  • Creatures you control gain menace and trample until end of turn.
  • Creatures you don't control get -1/-1 until end of turn.
  • Create two tapped Powerstone tokens.