rare n gargantuan air dragon elemental 

Perception +34; darkvision, mist vision, scent (imprecise) 60 feet

Languages Auran, Common, Draconic, Jotun, Sylvan

Skills Acrobatics +35, Athletics +38, Deception +34, Diplomacy +34, Intimidation +36, Nature +32, Stealth +35, Survival +36

Str +9 Dex +5 Con +7 Int +5 Wis +7 Cha +7

Mist Vision Fog and mist don't impair a cloud dragon's vision; they ignore the concealed condition from fog and mist.

AC  44; Fort +36, Ref +32, Will +34

HP 355; Immunities electricity, paralyzed, sleep

Frightful Presence (aura, emotion, fear, mental) 90 feet, DC 40

Deflecting Cloud [R] Trigger The dragon is the target of a ranged attack; Requirements The dragon is aware of the attack and has a free wing; Effect The cloud dragon flexes a wing and creates a billowing cloud of mist. The dragon is treated as if they were hidden for the purposes of resolving the triggering attack, so normally the attacker must succeed at a DC 11 flat check to target them. The dragon also gains a +4 circumstance bonus to AC against the triggering attack.

Speed 60 feet, fly 160 feet; cloud walk

Melee [>] jaws +36 (electricity, magical, reach 20 feet, sonic), Damage 3d10+17 piercing plus 2d12 electricity, 4d6 sonic, and thundering bite

Melee [>] claw +36 (agile, magical, reach 15 feet), Damage 4d10+17 slashing

Melee [>] tail +34 (magical, reach 25 feet), Damage 4d12+17 bludgeoning

Melee [>] horn +34 (deadly d12, magical, reach 20 feet), Damage 3d12+17 piercing

Primal Innate Spells DC 42; 8th wind walk; 5th cloudkill; 4th gust of wind (at will), solid fog, wall of wind (at will)

Breath Weapon [>>] (electricity, evocation, primal) The dragon breathes a thundercloud that deals 20d6 electricity damage in a 60-foot cone (DC 41 basic Reflex save). This cloud remains in the area for 1d4 rounds, with the effects of obscuring mist. A creature that ends its turn inside of the cloud takes 10d6 electricity damage (DC 41 basic Reflex save). The cloud dragon can't use Breath Weapon again for 1d4 rounds.

Cloud Form [>] (polymorph, primal, transmutation) The cloud dragon's body becomes vaporous and misty. They gain the effects of gaseous form, except their fly Speed remains unchanged. The cloud dragon can use this action again to return to physical form.

Cloud Walk The cloud dragon can tread on clouds or fog as though on solid ground.

Draconic Frenzy [>>] The dragon makes two claw Strikes and one horn Strike in any order.

Draconic Momentum The dragon recharges their Breath Weapon whenever they score a critical hit with a Strike.

Thundering Bite An ancient cloud dragon's jaws Strike creates a deafening clap of thunder when it damages a foe. A creature that takes damage from the dragon's jaws Strike must succeed at a DC 41 Fortitude save or be deafened for 1 minute (or permanently on a critical failure).

Bestiary 2, page 90.