Ice Walk. The dragon can move across and climb icy surfaces without needing to make an ability check. Additionally, difficult terrain composed of ice or snow doesn't cost it extra movement.

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

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 15 (2d10 + 4) piercing damage plus 3 (1d6) cold damage plus 3 (1d6) lightning.

Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.

Tail. Melee Weapon Attack: +8 to hit, reach 15 ft., one target. Hit: 11 (2d6+ 4) bludgeoning damage.

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 16 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.

Cold Breath (Recharge 5–6). The dragon exhales an icy blast in a 30-foot cone. Each creature in that area must make a DC 16 Constitution saving throw, taking 50 (11d8) cold damage on a failed save, or half as much damage on a successful one.

Lightning Breath (Recharge 5–6). The dragon exhales lightning in an 60-foot line that is 5 feet wide. Each creature in that line must make a DC 16 Dexterity saving throw, taking 50 (9d10) lightning damage on a failed save, or half as much damage on a successful one.