Ceremonial Knife is a common Artifact — Equipment card from Innistrad: Double Feature (DBL), collector number 521. Current market price: $0.35 (foil $1.35), TCGplayer market prices via Scryfall.
Equipped creature gets +1/+0 and has "Whenever this creature deals combat damage, create a Blood token." (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.") Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)