Rith, the Awakener is a rare Legendary Creature — Dragon card from Dominaria Remastered (DMR), collector number 366. Current market price: $0.23 (foil $0.34), TCGplayer market prices via Scryfall.
Flying Whenever Rith deals combat damage to a player, you may pay {2}{G}. If you do, choose a color, then create a 1/1 green Saproling creature token for each permanent of that color.