Ghalta, Primal Hunger is a rare Legendary Creature — Elder Dinosaur card from Special Guests (SPG), collector number 11. Current market price: $15.17 (foil $24.03), TCGplayer market prices via Scryfall.
This spell costs {X} less to cast, where X is the total power of creatures you control. Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)