Keen Smell. The dragon has advantage on Wisdom (Perception) checks that rely on smell.

 Magic Resistance. The dragon has advantage on saving throws against spells and other magical effects.

Multiattack. The dragon makes three attacks: one with its bite and two with its claws. Alternatively the dragon can replace one of it's bite attacks with it's gore attack

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) piercing damage.

Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.

Gore. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 17 (2d12 + 4) piercing damage.

 Galvanice Breath (Recharge 5–6). The dragon exhales a 30-foot cone composed of icy hail and crackling electricity. Each creature in that area must make a DC 18 Dexterity saving throw, taking 22 (4d10) cold damage and taking 22 (4d10) lightning damage on a failed save, or half as much damage on a successful one.

Innate Spellcasting. The dragon casts one of the following spells, requiring no spell components and using Charisma as the spellcasting ability (spell save DC 13):

1/day each: jump (self only)

Alternate Form. The dragon magically polymorphs into a beast or monstrosity that is of large size or smaller, 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.