Aether Chaser (AER) from Aether Revolt, available at 401 Games Canada.

• Rarity: Common
• Finish: Normal
• Artist: Jason Rainville
• Card Text:
  First strike
  When Aether Chaser enters the battlefield, you get EE (two energy counters).
  Whenever Aether Chaser attacks, you may pay EE. If you do, create a 1/1 colorless Servo artifact creature token.