Ashaya, Soul of the Wild is a mythic Legendary Creature — Elemental card from Zendikar Rising Promos (PZNR), collector number 179p. Current market price: $20.73 (foil $21.36), TCGplayer market prices via Scryfall.
Ashaya's power and toughness are each equal to the number of lands you control. Nontoken creatures you control are Forest lands in addition to their other types. (They're still affected by summoning sickness.)