The World Tree is a rare Land card from Kaldheim Promos (PKHM), collector number 275s. Current market price: — (foil $11.64), TCGplayer market prices via Scryfall.
This land enters tapped. {T}: Add {G}. As long as you control six or more lands, lands you control have "{T}: Add one mana of any color." {W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice this land: Search your library for any number of God cards, put them onto the battlefield, then shuffle.