Timeless Witness is a uncommon Creature — Human Shaman card from Modern Horizons 2 (MH2), collector number 358. Current market price: $0.34 (foil $0.95), TCGplayer market prices via Scryfall.
When this creature enters, return target card from your graveyard to your hand. Eternalize {5}{G}{G} ({5}{G}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Human Shaman with no mana cost. Eternalize only as a sorcery.)