Concealed Weapon is a uncommon Artifact — Equipment card from Murders at Karlov Manor (MKM), collector number 117. Current market price: $0.21 (foil $0.15), TCGplayer market prices via Scryfall.
Equipped creature gets +3/+0. Disguise {2}{R} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.) When this Equipment is turned face up, attach it to target creature you control. Equip {1}{R}