Anafenza, Kin-Tree Spirit is a rare Legendary Creature — Spirit Soldier card from Dragons of Tarkir (DTK), collector number 2. Current market price: $0.26 (foil $0.98), TCGplayer market prices via Scryfall.
Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)