Living Lore is a uncommon Creature — Avatar card from Commander 2021 (C21), collector number 121. Current market price: $0.17, TCGplayer market prices via Scryfall.
As this creature enters, exile an instant or sorcery card from your graveyard. Living Lore's power and toughness are each equal to the exiled card's mana value. Whenever this creature deals combat damage, you may sacrifice it. If you do, you may cast the exiled card without paying its mana cost.