The Black Arrow is a uncommon Legendary Artifact — Equipment card from The Hobbit (HOB), collector number 171. Current market price: $0.15 (foil $0.27), TCGplayer market prices via Scryfall.
Flash When The Black Arrow enters, it deals 1 damage to any target. If a Dragon is dealt damage this way, destroy it. Equipped creature gets +1/+1 and has reach. Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)