Ancient Skeletal Dragon

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: +7 to hit, reach 15 ft., one target. Hit: 15 (2d10 + 5) piercing damage.

Claw. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 5) slashing damage.

Tail. Melee Weapon Attack: +7 to hit, reach 20 ft., one target. Hit: 13 (2d8 + 5) 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 17 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.

Shard Breath The skeleton exhales a 90 ft. cone of bone shards, which deals 13d6 piercing damage. Creatures in the area must make a Dexterity saving throw DC17. On a successful save, the creature takes half the damage.

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.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 15 feet of the dragon must succeed on a DC 25 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.