Utility Knife is a common Artifact — Equipment card from Zendikar Rising (ZNR), collector number 256. Current market price: $0.06 (foil $0.25), TCGplayer market prices via Scryfall.
When this Equipment enters, attach it to target creature you control. Equipped creature gets +1/+1. Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)