Dragon, Ectoplasmic Wyrm (CR 25)

Gargantuan Dragon (Fire)
Alignment: Always chaotic neutral
Initiative: +2 (Dex); Senses: blindsense 60 ft., darkvision120 ft., low-light vision, and keen senses
Languages: Draconic

AC: 45 (-4 size, +2 Dex, +37 natural), touch 8, flat-footed 43
Hit Dice: 38d12+342 (589 hp); DR: 20/magic
Fort +30, Ref +23, Will +28
Speed: 40 ft., fly 250 ft. (clumsy), swim 80 ft.
Space: 40 ft./15 ft.
Base Attack +38; Grapple +66
Attack: 1 bite +50, 2 claws +45, 2 wings +45, 1 tail slap +45, 1 crush +45, 1 tail sweep +45
Damage: 1 bite 4d6+16, 2 claws 2d8+8, 2 wings 2d6, 1 tail slap 2d8, 1 crush 4d6, 1 tail sweep 2d6
Special Attacks/Actions: Breath weapon 22d8 (37)
Abilities: Str 43, Dex 14, Con 29, Int 30, Wis 25, Cha 23
Special Qualities: Planar travel, ectoplasm immunity, Ectoplasmic cocoon, Chameleon, Negate psionics, Dismiss ectoplasm, Energy barrier, Catapsi, whitefire aura 20d4, Manifester Lvl 17th, PR 30, SR 29, Fear aura (DC 35)
Feats: #Feats: 13
Skills: Skill points: 386
Advancement: 39-40 HD
Climate/Terrain: Demiplane of Ectoplasm, Astral Plane, underground
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: Double standard

Source: Web

Breath Weapon (Su): An ectoplasmic dragon has one breath weapon: a burst of whitefire. The radius and range of the breath weapon are listed in the chart. They spit out a glob of raw ectoplasm that explodes upon reaching the desired range.

Dragon Size*Maximum RangeRadius
Tiny*30 feet5 feet
Small*40 feet10 feet
Medium60 feet15 feet
Large80 feet20 feet
Huge100 feet25 feet
Gargantuan120 feet30 feet
Colossal140 feet35 feet

* Though ectoplasmic dragons cannot be smaller than Medium, these sizes were included for completeness.

Planar Travel (Su): Ectoplasmic dragons have the innate ability to pass instantly between the Material Plane and the Astral Plane as a standard action.

Psionics (Sp): 3/day -- chameleon, dismiss ectoplasm, ectoplasmic cocoon, negate psionics; 2/day -- energy barrier; 1/day -- catapsi, mass cocoon. Manifester level varies by age; save DC 10 + dragon's Intelligence modifier + power level. An ectoplasmic dragon manifests powers and gains additional attack and defense modes as if it were a psion with Metacreativity as its primary discipline.

Attack/Defense Modes: Id insinuation/mental barrier.

Whitefire Aura (Su): The ectoplasmic dragon can initiate its whitefire aura once per day as a standard action. It lasts 1 round per age category of the dragon. While the aura lasts, any creature striking the dragon with a natural or a handheld weapon deals normal damage, but at the same time the attacker takes the whitefire damage listed. If the attacker makes a successful Reflex save (DC same as frightful presence), it reduces damage by half.

Ectoplasm Immunity (Ex): An ectoplasmic dragon is not effected by the dismiss ectoplasm power.

Fire Subtype

A creature with the fire subtype has immunity to fire. It has vulnerability to cold, which means it takes half again as much (+50%) damage as normal from cold, regardless of whether a saving throw is allowed, or if the save is a success or failure.