Titania, Nature's Force is a mythic Legendary Creature — Elemental card from The Brothers' War Commander (BRC), collector number 25. Current market price: $3.52 (foil $5.84), TCGplayer market prices via Scryfall.
You may play Forests from your graveyard. Whenever a Forest you control enters, create a 5/3 green Elemental creature token. Whenever an Elemental you control dies, you may mill three cards.