Kaervek, the Punisher is a rare Legendary Creature — Human Warlock card from Outlaws of Thunder Junction (OTJ), collector number 289. Current market price: $0.39 (foil $0.38), TCGplayer market prices via Scryfall.
Whenever you commit a crime, exile up to one target black card from your graveyard and copy it. You may cast the copy. If you do, you lose 2 life. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime. Copies of permanent spells become tokens.)