Freelance Muscle is a uncommon Creature — Rhino Warrior card from Streets of New Capenna (SNC), collector number 147. Current market price: $0.22 (foil $0.22), TCGplayer market prices via Scryfall.
Whenever this creature attacks or blocks, it gets +X/+X until end of turn, where X is the greatest power and/or toughness among other creatures you control.