Adult Tungsten Dragon

Empowered Attacks. The dragon's weapon attacks count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks.

Immutable Form. The dragon is immune to any spell or effect that would alter its form.

Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.

Magic Susceptibility. The dragon has disadvantage on saving throws against spells and other magical effects.

Innate Spellcasting. The dragon's spellcasting ability is Charisma (spell save DC 17, +9 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

1/day each: steel wind strike, insect plague, magic weapon (4th level), greater restoration

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 20 (2d12 + 7) piercing damage.

Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 16 (2d8 + 7) slashing damage.

Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 18 (2d10 + 7) bludgeoning damage.

Frightful Presence. Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 17 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Breath Weapons (Recharge 5–6). The dragon uses one of the following breath weapons.

Poison Breath. The dragon exhales poisonous gas in a 60-foot cone. Each creature in that area must make a DC 22 Dexterity saving throw, taking 55 (10d10) poison damage on a failed save, or half as much damage on a successful one.

Susceptibility Breath. The dragon exhales gas in a 60-foot cone. Each creature in that area must succeed on a DC 22 Constitution saving throw or have disadvantage on Constitution saving throws for 1 minute. Additionally, when a creature takes damage under this effect, it must succeed on a DC 12 Constitution saving throw or take double damage. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Change Shape. The dragon magically polymorphs into a humanoid or beast that has a challenge rating no higher than its own, or 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 (the dragon's choice).

In a new form, the dragon retains its alignment, hit points, Hit Dice, ability to speak, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form.

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The dragon regains spent legendary actions at the start of its turn.

Detect. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 30 feet of the dragon must succeed on a DC 20 Dexterity saving throw or take 18 (2d10 + 7) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.

Amplify Gravity (3 Actions). The dragon attempts to magically increase the weight of a creature within 120 feet. The target must succeed on a DC 17 Wisdom saving throw or be affected by this. While affected by this, the target must make a DC 17 Strength saving throw at the start of each of their turns. On a failed save, the target is restrained until the start of their next turn. They also take bludgeoning damage equal to one of their hit dice. This effect ends after 1 minute.