Postmortem Professor is a rare Creature — Zombie Warlock card from Secrets of Strixhaven Promos (PSOS), collector number 93p. Current market price: $0.65 (foil $1.01), TCGplayer market prices via Scryfall.
This creature can't block. Whenever this creature attacks, each opponent loses 1 life and you gain 1 life. {1}{B}, Exile an instant or sorcery card from your graveyard: Return this card from your graveyard to the battlefield.