Chimeric Mass (SOM) from Scars of Mirrodin, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: David Palumbo
• Card Text:
  Chimeric Mass enters the battlefield with X charge counters on it.
  1: Until end of turn, Chimeric Mass becomes a Construct artifact creature with "This creature's power and toughness are each equal to the number of charge counters on it."