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

Frost Aura. The dragon is sheathed in chilling winds and ice. When a creature steps within 10ft for the first time on a turn or starts its turn there, it starts to freeze and takes 7 (2d6) cold damage, The Creature also takes this damage if it hits the Dragon with a melee weapon attack. The dragon's aura freezes any liquids within 10ft of the dragon. The dragon can toggle this aura as a bonus action.

Magic Attacks. The Dragon's attacks count as magical

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 7 (2d6) cold damage.

Claw. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 15 (2d6 + 8) slashing damage plus 7 (2d6) cold damage.

Tail. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage plus 7 (2d6) cold 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 19 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 icy winds in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 63 (18d6) cold damage on a failed save, or half as much damage on a successful one.

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.

Tail Attack. The dragon makes a tail attack.

Ice Burst (Costs 2 Actions). The creates a shockwave of icy shrapnel. Each creature within 10 feet of the dragon must succeed on a DC 22 Dexterity saving throw or take 19 (2d6 + 8) piercing damage plus 7 (2d6) cold damage and be knocked prone. The dragon can then fly up to half its flying speed.