Gust Walker (AKH) from Amonkhet, available at 401 Games Canada.

• Rarity: Common
• Finish: Normal
• Artist: Jason Rainville
• Card Text:
  You may exert Gust Walker as it attacks. When you do, it gets +1/+1 and gains flying until end of turn. (An exerted creature won't untap during your next untap step.)