The Earth King is a rare Legendary Creature — Human Noble Ally card from Avatar: The Last Airbender Promos (PTLA), collector number 172s. Current market price: — (foil $7.40), TCGplayer market prices via Scryfall.
When The Earth King enters, create a 4/4 green Bear creature token. Whenever one or more creatures you control with power 4 or greater attack, search your library for up to that many basic land cards, put them onto the battlefield tapped, then shuffle.