Goldspan Dragon [Modern Horizons 3 Commander] Fourth Edition (Foreign Black Border) and they may spend mana

and they may spend mana as though it were mana of any color to cast that spell

4RG: Other creatures you control get +1/+1 and gain trample and haste until end of turn

Set: Mystery Booster Type: Enchantment Rarity: Rare Cost: {1}{R} Cumulative upkeep—Add {R}

Set: Strixhaven: School of Mages Prerelease Promos Type: Legendary Creature — Vampire Warlock Rarity: Rare Cost: {B} Menace

and it can't be blocked

Goldspan Dragon [Modern Horizons 3 Commander] Fourth Edition (Foreign Black Border) and they may spend manaSet: Modern Horizons 3 Commander Type: Creature Dragon Rarity: Mythic Cost: {3}{R}{R} Flying, haste Whenever Goldspan Dragon attacks or becomes the target of a spell, create a Treasure token. Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."