Kingpin's Pet is a common Creature — Thrull card from Gatecrash (GTC), collector number 173. Current market price: $0.10 (foil $0.66), TCGplayer market prices via Scryfall.
Flying Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)