Elite Scaleguard (CM2) from Commander Anthology Volume II, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Steve Prescott
• Card Text:
  When Elite Scaleguard enters the battlefield, bolster 2. (Choose a creature with the least toughness among creatures you control and put two +1/+1 counters on it.)
  Whenever a creature you control with a +1/+1 counter on it attacks, tap target creature defending player controls.