Viridian Longbow is a common Artifact — Equipment card from Mirrodin (MRD), collector number 270. Current market price: $1.44 (foil $12.63), TCGplayer market prices via Scryfall.
Equipped creature has "{T}: This creature deals 1 damage to any target." Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)