Dragon, Astral Great Wyrm (CR 24)

Colossal Dragon (Extraplanar)
Alignment: Always neutral
Initiative: +1 (Dex); Senses: blindsense 60 ft., darkvision120 ft., low-light vision, and keen senses
Languages: Never speaks to Astral Plane non-natives

AC: 40 (-8 size, +1 Dex, +37 natural), touch 3, flat-footed 39
Hit Dice: 38d12+266 (513 hp); DR: 20/holy or unholy
Fort +28, Ref +22, Will +29
Speed: 30 ft., fly 200 ft. (poor)
Space: 80 ft./15 ft.
Base Attack +38; Grapple +65
Attack: 1 bite +41, 2 claws +36, 2 wings +36, 1 tail slap +36, 1 crush +36, 1 tail sweep +36
Damage: 1 bite 4d8+11, 2 claws 4d6+5, 2 wings 2d8, 1 tail slap 4d6, 1 crush 4d8, 1 tail sweep 2d8
Special Attacks/Actions: Breath weapon 20d6 (36)
Abilities: Str 33, Dex 13, Con 24, Int 26, Wis 27, Cha 26
Special Qualities: Astral familiarity, detect extraplanar, Eagles splendor, Null gravity aura, Severing bite, touch of idiocy, Detect animals or plants, Banishment, Mass cocoon, Manifester Lvl 19th, PR 31, SR 29, Fear aura (DC 37)
Feats: #Feats: 13
Skills: Skill points: 310
Advancement: 39+ HD
Climate/Terrain: Astral Plane
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 #344

Breath Weapon (Su): An astral dragon has two types of breath weapon, a line of dismissal and a cone of scouring dust. A creature struck by an astral dragon's line breath weapon must succeed at a Will save or instantly return to its home plane, as per the dismissal spell. Like that spell, there is a 20% chance the astral dragon's line breath weapon actually sends the subject to a plane other than its own (but never back to the Astral Plane).

Creatures within the cone of dust take the damage listed from a storm of scouring astral wind that flays the skin like a sandstorm. A Reflex save halves the damage.

Spell-Like Abilities: 3/day - eagle's splendor, touch of idiocy; 1/day - banishment, detect animals or plants.

Astral Familiarity (Ex): An astral dragon moves through the Astral Plane as if its Wisdom were 8 points higher than it really is when making a check to alter the subjective directional gravity.

Detect Extraplanar (Su): An astral dragon can continuously detect creatures not native to the Astral Plane. This acts in most ways like the detect evil spell, but it extends to a range of 30 feet per age category and it does not actually detect the creature's alignment - only that the creature isn't native to the Astral Plane. An astral dragon can determine a creature's nature after concentrating for a single round (no additional information is provided by multiple rounds of concentration). The astral dragon can suppress or resume this ability as a free action.

Null Gravity Aura (Su): A young or older astral dragon radiates a field of null gravity, changing the area around it from subjective direction gravity to no gravity. Those within the area merely float unless they possess flight or some other means of magical movement. See Astral Plane for information on the effects of gravity on the Astral Plane. This aura has a radius of 30 feet plus 30 feet per age category beyond young. This aura does not affect the astral dragon, allowing it to use subjective direction gravity and its flight to move at incredible speeds. An astral dragon can suppress or resume this ability as a free action.

Severing Bite (Su): A juvenile or older astral dragon's bite severs silver cords on a successful critical hit in addition to dealing extra damage.

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.