Goblin Banneret is a uncommon Creature — Goblin Soldier card from Guilds of Ravnica (GRN), collector number 102. Current market price: $0.21 (foil $0.30), TCGplayer market prices via Scryfall.
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) {1}{R}: This creature gets +2/+0 until end of turn.