Ephemeral Shroud. The Cloud Wyrm´s body is surrounded by swirling mist, granting it advantage on Dexterity (Stealth) checks and disadvantage on Wisdom (Perception) checks made to spot the dragon.

Frightful Ephemera. While flying, the Cloud Wyrm can use its "Frightful Presence" as an action. Additionally, the Cloud Wyrm´s "Ephemeral Shroud" ability extends to its "Frightful Presence" area, causing even more confusion and fear among those affected.

Multiattack. The Cloud Wyrm 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 15 ft., one target. Hit: 20 (2d10 + 8) piercing damage plus 10 (3d6) cold damage.

Claw. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 16 (2d6 + 8) slashing damage.

Tail Slap. Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 18 (2d8 + 8) bludgeoning damage.

Breath Weapon (Recharge 5–6). The Cloud Wyrm exhales a blast of freezing mist in a 60-foot cone. Each creature in that area must make a DC 20 Constitution saving throw, taking 63 (18d6) cold damage on a failed save, or half as much damage on a successful one. The mist lingers for 1 minute, heavily obscuring the area and granting the Cloud Wyrm advantage on Dexterity saving throws.

Legendary Actions

The Cloud Wyrm 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 Cloud Wyrm regains spent legendary actions at the start of its turn.

Detect. The Cloud Wyrm makes a Wisdom (Perception) check.

Wing Attack (Costs 2 Actions). The Cloud Wyrm beats its wings. Each creature within 15 feet of the dragon must succeed on a DC 22 Dexterity saving throw or take 14 (2d6 + 7) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.

Cloud Surge (Costs 3 Actions). The Cloud Wyrm summons a burst of swirling cloud energy. Each creature within 30 feet of the Cloud Wyrm  must succeed on a DC 20 Strength saving throw or be pushed 20 feet away from the Cloud Wyrm and knocked prone.