Brittle Dragon

Ice Glide. The dragon can burrow through nonmagical, unworked ice and snow. While doing so, the dragon doesn't doesn't disturb the material it moves through.

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

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

Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 6 (1d8 + 2) cold damage.

Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.

Tail. Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 20 (2d10 + 9) slashing 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 15 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.

Chilling Breath (Recharge 6). The dragon exhales an icy blast in an 80-foot cone. Each creature in that area must make a DC 21 Constitution saving throw, taking 63 (14d8) cold damage on a failed save, or half as much damage on a successful one.

If a creature fails by 5 or more, it magically begins to turn to ice and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restoration spell or other magic.

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.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 10 feet of the dragon must succeed on a DC 20 Dexterity saving throw or take 16 (2d6 + 8) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.