Young Coming of Age Bronze Dragon

Amphibious. The dragon can breathe air and water.

Multiattack. The dragon makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 5) piercing damage.

Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.

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

Lightning Breath. The dragon exhales lightning in a 60- foot line that is 5 feet wide. Each creature in that line must make a DC 15 Dexterity saving throw, taking 55 (10d10) lightning damage on a failed save, or half as much damage on a successful one.

Repulsion Breath. The dragon exhales repulsion energy in a 30-foot cone. Each creature in that area must succeed on a DC 15 Strength saving throw. On a failed save, the creature is pushed 40 feet away from the dragon.

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 14 Wisdom saving throw or become frightened until the end of its next turn. 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.

Attempt to Change Shape. This is an Adult Dragon Skill trying to be mastered. Roll a D20. On a n+10 or higher this ability works as intended. Otherwise the roll fails. If the roll is <n there are unintended consequences. After a long rest n resets to 2. On a success n decreases by 1 with a minimum of 0. On a failed attempt n increases by 2. 

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.