Dragon, Shadow Wyrm (CR 22)

Gargantuan Dragon
Alignment: Always chaotic evil
Initiative: +0; Senses: blindsense 60 ft., darkvision120 ft., low-light vision, and keen senses
Languages: Draconic

AC: 43 (-4 size, +37 natural), touch 6, flat-footed 43
Hit Dice: 34d12+238 (459 hp); DR: 20/magic
Fort +26, Ref +19, Will +29
Speed: 80 ft., fly 150 ft. (clumsy)
Space: 40 ft./15 ft.
Base Attack +34; Grapple +57
Attack: 1 bite +41, 2 claws +36, 2 wings +36, 1 tail slap +36, 1 crush +36, 1 tail sweep +36
Damage: 1 bite 4d6+11, 2 claws 2d8+5, 2 wings 2d6, 1 tail slap 2d8, 1 crush 4d6, 1 tail sweep 2d6
Special Attacks/Actions: Breath weapon 7(DC 37)
Abilities: Str 33, Dex 10, Con 25, Int 30, Wis 30, Cha 31
Special Qualities: Energy drain immunity, Shadow blend, Mirror Image, Dimension door, Nondetection, Shadow walk, Frightful Presence DC37, SR 31
Feats: #Feats: 12
Skills: Skill points: 346
Advancement: 35-36 HD (Gargantuan)
Climate/Terrain: 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: Triple Standard

Source: Draconomicon

Breath Weapon (Su): A shadow dragons breath weapon is a cone of billowing, smoky shadows with an energy drain effect. Creatures within the cone gain 7 negative levels: the saving throw to remove the negative level is 37. A successful Reflex save (DC 37) reduces the number of negative levels by half (round down).

Shadow Blend (Su): During any conditions other than full daylight, a shadow dragon can disappear into the shadows, giving it nine-tenths concealment. Artificial illumination, even a light or continual flame spell, does not negate this ability. A daylight spell, however, will.