Amphibious. The dragon can breathe air and water.

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

Multiattack. The dragon can use its Calming Presence. It then makes three attacks: one with its bite and two with its tail. Or it can use it's Action to Constrict, or use a breathe attack. 

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 3) piercing damage.

Tail. Melee Weapon Attack: +8 to hit, reach 20 ft., one target. Hit: 14 (2d8 + 3) bludgeoning damage.

Constrict. Melee Weapon Attack: +8 to hit, reach 5 ft., one creature. Hit: 24 (6d6 + 3)bludgeoning damage, and the target is grappled (escape DC 19). Until this grapple ends, the creature is restrained, and the dragon can't constrict another target.

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 18 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.

Moonlit Breath. The dragon releases a beam of moonlight in a 60-foot cone. Each creature in that area must make a DC 18 Constitution saving throw, taking 45 (12d6) Radiant damage on a failed save, or half as much damage on a successful one.

A shapechanger makes its saving throw with disadvantage. If it fails, it also instantly reverts to its original form and can't assume a different form until it leaves the spell's light.

Midas Breath. The dragon exhales a strange magical gas in a 60-foot cone. Each creature in that area must succeed on a DC 17 Constitution saving throw or will be slowly turned to Gold, and are restrained as their flesh begins to harden. On a successful save, the creature isn't affected.

A creature restrained by this spell must make another Constitution saving throw at the end of each of its turns. If it successfully saves against this spell three times, the spell ends. If it fails its saves three times, it is turned to stone and subjected to the petrified condition for the duration. The successes and failures don't need to be consecutive; keep track of both until the target collects three of a kind. (Nat 1s count as 2 failures, and Nat 20s as 2 successes).

If the creature is physically broken, melted, or befalls other harm while petrified, it suffers from similar deformities if it reverts to its original state.

If the dragon is killed before the spell is completed, the magic is undone, but once a creature is turned to gold, it remains cursed in that fashion until the effects of the Gold Pearl's breathe can be undone.

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.

Constrict. The dragon Constricts.

Consume Success; Pearl dragons have the unique ability to Consume/be empowered by different things, and convert the energy from that into pearls for their horde. Gold Pearl Dragons feed on, and greatly enjoy eating, the wealth and good fortune of others. During combat, this allows them to use their reaction to impose disadvantage on a saving throw or roll to attack, even after it has been made.

They may also consume currency straight from the pockets of anyone within 20ft as a bonus action... slowly causing Wealth to deplete at a rate of 1 gold per turn unless an attack breaks their concentration. (DC 18) Once their concentration is broken, their devouring of your monetary gains also ceases... but the only way to retrieve what was lost is to slay the Gold Pearl Dragon.

Gold is their Favorite food.