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: +10 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage.

Claw.

Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.

Breath Weapons (Recharge 5–6).

The dragon uses one of the following breath weapons.

Fire Breath. The dragon exhales fire in a 30-foot cone. Each creature in that area must make a DC 17 Dexterity saving throw, taking 55 (10d10) fire damage on a failed save, or half as much damage on a successful one.
Weakening Breath. The dragon exhales gas in a 30-foot cone. Each creature in that area must succeed on a DC 17 Strength saving throw or have disadvantage on Strength-based attack rolls, Strength checks, and Strength saving throws 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.

Young Gold Dragon