Graf Rats // Chittering Host (EMN) from Eldritch Moon, available at 401 Games Canada.

• Rarity: Common
• Finish: Normal
• Artist: Jason Felix
• Card Text:
  At the beginning of combat on your turn, if you both own and control Graf Rats and a creature named Midnight Scavengers, exile them, then meld them into Chittering Host.
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  Meld Partner: Midnight Scavengers
  When Melded, it becomes the following:
  Chittering Host
  Creature — Eldrazi Horror
  Haste
  Menace (This creature can't be blocked except by two or more creatures.)
  When Chittering Host enters the battlefield, other creatures you control get +1/+0 and gain menace until end of turn.
  5/6