Minor Immutability. The dragon has advantage on saving throws against its form being changed in any way.

Rock Supreme Camouflage. The dragon's Stealth modifier is doubled while the dragon is trying to hide in rocky and/or snowy terrain. 

Multiattack. The dragon makes three attacks: one with its bite and two with its claws. It can replace the claw attacks with Fireball attacks.

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 4) piercing damage plus 2 (1d4) fire or cold damage (dragon's choice).

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage.

Fireball. Melee Weapon Attack: +7 to hit, range 15/60 ft., one target. Hit: 7 (2d6) fire or cold damage (dragon's choice) plus 3 (1d6) bludgeoning damage.

Coldfire Breath (Recharge 6). The dragon exhales a blast of icy fire in a 30-foot cone. Each creature in that area must make a DC 16 Constitution saving throw, taking 14 (4d6) fire damage plus 14 (4d6) cold damage on a failed save, or half as much damage on a successful one.

Cloak (Recharge 1/Short or Long Rest). The dragon casts invisibility, targeting itself.