Gladehart Cavalry is a rare Creature — Elf Knight card from Oath of the Gatewatch (OGW), collector number 132. Current market price: $0.29 (foil $0.37), TCGplayer market prices via Scryfall.
When this creature enters, support 6. (Put a +1/+1 counter on each of up to six other target creatures.) Whenever a creature you control with a +1/+1 counter on it dies, you gain 2 life.