Ancient Gold Dragon

The dragon can breathe air and water.

If the dragon fails a saving throw, it can choose to succeed instead.

The dragon makes one Rend attack and uses Fire Breath.

Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 2d8+10 slashing damage plus 2d8 fire damage.

The dragon exhales fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 13d10 fire damage on a failed save, or half as much damage on a successful one.

The dragon exhales a weakening breath in a 90-foot cone. Each creature in that area must make a DC 24 Strength saving throw. On a failure, the creature has disadvantage on Strength-based D20 tests and subtracts 5 from its damage rolls for 1 minute. It repeats the save at the end of each of its turns, ending the effect on itself on a success.

The dragon casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 24): At will: Detect Magic, Guiding Bolt (level 4 version), Shapechange (Beast or Humanoid form only, no Temporary Hit Points gained from the spell, and no Concentration or Temporary Hit Points required to maintain the spell) 1/day each: Flame Strike (level 6 version), Word of Recall, Zone of Truth