Skinthinner is a common Creature — Zombie card from Legions (LGN), collector number 80. Current market price: $0.30 (foil $1.55), TCGplayer market prices via Scryfall.
Morph {3}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, destroy target nonblack creature. It can't be regenerated.