Goblin Banneret (GRN) from Guilds of Ravnica, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Viktor Titov
• Card Text:
  Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
  1R: Goblin Banneret gets +2/+0 until end of turn.