Ancient Brass Dragon

The dragons spellcasting ability is Charisma (save DC 19). It can innately cast the following spells, requiring no material components.

• 3/Day Each: comprehend languages, Identify, Commune, Legend Lore
• 1/Day: Teleport, True Seeing

When the dragon fails a saving throw, it can choose to succeed instead. When it does, some of its scales fall away and turn to sand. If it has no more uses of this ability, its Armor Class is reduced to 18 until it finishes a long rest.

The brass dragon gains a d4 expertise die on Intelligence checks made to recall lore. If it fails such a roll, it can expend one use of its Legendary Resistance trait to treat the roll as a 20.

The brass dragon can subsist on only a quart of water and a pound of food per day.

Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: 30 (4d10 + 8) piercing damage plus 9 (2d8) fire damage.

The dragon uses one of the following breath weapons:

The dragon magically takes the shape of a humanoid or beast or changes back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (dragons choice). In the new form the dragons stats are unchanged except for its size. It can't use Molten Spit Breath Weapons Tail Attack or Wing Attack except in dragon form. In beast form it can attack only with its bite and claws if appropriate to its form. If the beast form is Large or smaller the reach of these attacks is reduced to 5 feet. In humanoid form it can attack only with its staff.

Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 8) slashing damage.

The dragon exhales molten glass in a 90-foot-long 10-foot-wide line. Each creature in the area makes a DC 22 Dexterity saving throw taking 70 (20d6) fire damage on a failed save or half damage on a success. A creature that fails the save is also blinded until the end of its next turn.

The dragon targets a creature within 60 feet forcing it to make a DC 22 Dexterity saving throw. The creature takes 22 (4d10) fire damage on a failure or half damage on a success. A creature that fails the saving throw also takes 11 (2d10) ongoing fire damage. A creature can use an action to end the ongoing damage.

The dragon attacks once with its bite and twice with its claws. In place of its bite it can use Molten Spit.

The dragon exhales sleep gas in a 90-foot cone. Each creature in the area makes a DC 22 Constitution saving throw. On a failure a creature falls unconscious for 10 minutes or until it takes damage or someone uses an action to wake it.

Melee Weapon Attack: +15 to hit, reach 5 ft., one target. Hit: 12 (1d8 + 8) bludgeoning damage.

Melee Weapon Attack: +15 to hit, reach 20 ft., one target. Hit: 21 (3d8 + 8) bludgeoning damage and the dragon pushes the target 10 feet away.

When a creature the dragon can see within 10 feet hits the dragon with a melee attack, the dragon makes a tail attack against it.

The dragon evaluates one creature it can see within 60 feet. It learns the creatures resistances, immunities, vulnerabilities, and current and maximum hit points. That creatures next attack roll against the dragon before the start of the dragons next turn is made with disadvantage.

Each creature of the dragons choice within 120 feet that can hear it makes a DC 19 Charisma saving throw. On a failure, it is frightened for 1 minute. A creature repeats the saving throw at the end of its turns, ending the effect on itself on a success. When it succeeds on a saving throw or the effect ends for it, it is immune to Roar for 24 hours.

Only one legendary action can be used at a time and only at the end of another creatures turn. It regains spent legendary actions at the start of its turn.

The dragon beats its wings. Each creature within 15 feet makes a DC 23 Dexterity saving throw. On a failure, it is pushed 10 feet away and knocked prone. The dragon can then fly up to half its fly speed.