Rosethorn Halberd is a common Artifact — Equipment card from The List (PLST), collector number ELD-175. Current market price: $0.27, TCGplayer market prices via Scryfall.
When this Equipment enters, attach it to target non-Human creature you control. Equipped creature gets +2/+1. Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)