Impervious Greatwurm is a mythic Creature — Wurm card from Guilds of Ravnica (GRN), collector number 273. Current market price: — (foil $4.94), TCGplayer market prices via Scryfall.
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) Indestructible