Battlefield Scavenger is a uncommon Creature — Jackal Rogue card from Foundations Jumpstart (J25), collector number 520. Current market price: $0.22, TCGplayer market prices via Scryfall.
You may exert this creature as it attacks. (It won't untap during your next untap step.) Whenever you exert a creature, you may discard a card. If you do, draw a card.