Mortivore is a rare Creature — Lhurgoyf card from Commander Anthology Volume II (CM2), collector number 69. Current market price: $0.45, TCGplayer market prices via Scryfall.
Mortivore's power and toughness are each equal to the number of creature cards in all graveyards. {B}: Regenerate this creature. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)