Dragon, Arboreal Great Wyrm (CR 22)

Colossal Dragon (Extraplanar)
Alignment: Always chaotic good
Initiative: +0; Senses: blindsense 60 ft., darkvision120 ft., low-light vision, and keen senses
Languages: Celestial, Draconic, Elven, Sylvan

AC: 41 (-8 size, +39 natural), touch 2, flat-footed 41
Hit Dice: 38d12+418 (665 hp); DR: 20/magic and 10/lawful
Fort +32, Ref +21, Will +30
Speed: 60 ft., fly 250 ft. (clumsy)
Space: 80 ft./15 ft.
Base Attack +38; Grapple +69
Attack: 1 bite +45, 2 claws +40, 2 wings +40, 1 tail slap +40, 1 crush +40, 1 tail sweep +40
Damage: 1 bite 4d8+19, 2 claws 4d6+9, 2 wings 2d8, 1 tail slap 4d6, 1 crush 4d8, 1 tail sweep 2d8
Special Attacks/Actions: Breath weapon 24d8 (40)
Abilities: Str 49, Dex 10, Con 32, Int 24, Wis 29, Cha 27
Special Qualities: Immunity to acid, sonic and enchantment magic, Alternate form, Telekinesis, Baleful Polymorph, Ottos Irresistable Dance, Polymorph Any Object, SR 31, Fear aura (DC 37)
Feats: #Feats: 13
Skills: Skill points: 272
Advancement: 39+ HD (Colossal)
Climate/Terrain: Any land and underground (Olympian Planes of Arborea)
Organization: Solitary (1 dragon, any age), clutch (1d4+1 wyrmlings, very young, young, juvenile, or young adults), family (pair of mature adults and 1d4+1 offspring)
Treasure/Possessions: Triple Standard

Source: Dragon #321

Breath Weapon (Su): An arboreal dragon has one breath weapon, a cone of razor-sharp thorns that deal piercing damage. A creature within the cone may make a Reflex save to take half damage.

Alternate Form (Su): A young or older arboreal dragon can assume any animal, fey, or humanoid form of Medium size or smaller as a standard action three times per day. This ability functions as a polymorph spell cast on it by a 10th-level caster, except that the dragon does not regain hit points for changing form and can only assume the form of an animal, fey, or humanoid. The dragon can remain in its animal, fey, or humanoid form until it chooses to assume a new one or its natural form.

Spell-like Abilities: 3/day - telekinesis; baleful polymorph; 1/day - Otto's irresistible dance, polymorph any object.

Skills: Climb, Spellcraft, and Survival are considered class skills for arboreal dragons.

Extraplanar Subtype

A subtype applied to any creature when it is on a plane other than its native plane. A creature that travels the planes can gain or lose this subtype as it goes from plane to plane. This book assumes that encounters with creatures take place on the Material Plane, and every creature whose native plane is not the Material Plane has the extraplanar subtype (but would not have when on its home plane). An extraplanar creatures usually has a home plane mentioned in its description. These home planes are taken from the Great Wheel cosmology of the D&D game (see Chapter 5 of the Dungeon Master's Guide). If your campaign uses a different cosmology, you will need to assign different home planes to extraplanar creatures.

Creatures not labeled as extraplanar are natives of the Material Plane, and they gain the extraplanar subtype if they leave the Material Plane. No creature has the extraplanar subtype when it is on a transitive plane; the transitive planes in the D&D cosmology are the Astral Plane, the Ethereal Plane, and the Plane of Shadow.