First Sliver's Chosen (MH1) from Modern Horizons, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Steven Belledin
• Card Text:
  Sliver creatures you control have exalted. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)