Gluttonous Guest is a common Creature — Vampire card from Innistrad: Double Feature (DBL), collector number 381. Current market price: $0.21 (foil $0.74), TCGplayer market prices via Scryfall.
When this creature enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.") Whenever you sacrifice a Blood token, you gain 1 life.