uncommon le gargantuan amphibious dragon 

Perception +30; darkvision, scent (imprecise) 60 feet

Languages Abyssal, Common, Draconic, Elven, Jotun, Sylvan

Skills Acrobatics +25, Arcana +32, Athletics +30, Deception +27, Diplomacy +31, Intimidation +31, Nature +28, Occultism +34, Society +31, Stealth +29

Str +7 Dex +4 Con +5 Int +6 Wis +5 Cha +6

Camouflage The dragon can Hide in natural environments even if it doesn't have cover.

AC  41; Fort +30, Ref +29, Will +32; +1 status to all saves vs. magic

HP 315; Immunities poison, paralyzed, sleep

Frightful Presence (aura, emotion, fear, mental) 90 feet, DC 37

Miasma (aura, poison) 20 feet. After the dragon uses its Breath Weapon, a cloud of poison gas continues to emanate from its body for 1 round. Any creature that ends its turn in the miasma takes 4d6 poison damage (DC 37 basic Fortitude save). Any creature in the miasma is concealed and treats other creatures as concealed. The dragon can see through this concealment.

Twisting Tail [R] Trigger A creature within reach of the dragon's tail uses a move action or leaves a square during a move action it's using. Effect The dragon makes a tail Strike at the creature with a –2 penalty. If it hits, the dragon disrupts the creature's action.

Speed 50 feet, fly 200 feet, swim 50 feet; trackless step, woodland stride

Melee [>] jaws +33 (magical, poison, reach 20 feet), Damage 3d12+15 piercing plus 4d4 poison

Melee [>] claw +33 (agile, magical, reach 15 feet), Damage 3d10+15 slashing

Melee [>] tail +31 (magical, reach 25 feet), Damage 3d10+13 bludgeoning

Melee [>] horn +31 (magical, reach 20 feet), Damage 2d10+13 piercing

Arcane Innate Spells DC 39; 6th dominate; 4th charm (at will), suggestion; 2nd entangle (at will)

Breath Weapon [>>] (arcane, evocation, poison) The dragon breathes a toxic cloud that deals 18d6 poison damage in a 60-foot cone (DC 37 basic Fortitude save). The Breath Weapon also creates a miasma. The dragon can't use Breath Weapon again for 1d4 rounds.

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

Draconic Momentum The dragon recharges its Breath Weapon whenever it scores a critical hit with a Strike.

Trackless Step The green dragon always gains the benefits of Cover Tracks in natural surroundings, even while moving at full speed.

Woodland Stride The green dragon ignores difficult terrain and greater difficult terrain from non-magical foliage.

Bestiary, page 110.