Coin Dragon

Amphibious. The dragon can breathe air and water.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 7 (1d6 + 2) piercing damage.
Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 3 (1d4 + 1) slashing damage.
Breath Weapons (Recharge 6). The dragon uses one of the following breath weapons.
Fire Breath. The dragon exhales fire in a 5-foot cone. Each creature in that area must make a DC 13 Dexterity saving throw, taking 5 (1d8) fire damage on a failed save, or half as much damage on a successful one.
Weakening Breath. The dragon exhales gas in a 5-foot cone. Each creature in that area must succeed on a DC 13 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.