World Shaper is a rare Creature — Merfolk Shaman card from Rivals of Ixalan Promos (PRIX), collector number 151p. Current market price: $12.51 (foil $13.00), TCGplayer market prices via Scryfall.
Whenever this creature attacks, you may mill three cards. When this creature dies, return all land cards from your graveyard to the battlefield tapped.