Dragon, Shadow Adult (CR 13)

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

AC: 31 (-1 size, +22 natural), touch 9, flat-footed 31
Hit Dice: 19d12+37 (180 hp); DR: 5/magic
Fort +14, Ref +11, Will +16
Speed: 80 ft., fly 150 ft. (poor)
Space: 10 ft./10 ft.
Base Attack +19; Grapple +27
Attack: 1 bite +22, 2 claws +17, 2 wings +17, 1 tail slap +17
Damage: 1 bite 2d6+4, 2 claws 1d8+2, 2 wings 1d6, 1 tail slap 1d8
Special Attacks/Actions: Breath weapon 3(DC 24)
Abilities: Str 19, Dex 10, Con 17, Int 20, Wis 20, Cha 21
Special Qualities: Energy drain immunity, Shadow blend, Mirror Image, Dimension door, Frightful Presence DC 24, SR 22
Feats: #Feats: 7
Skills: Skill points: 101
Advancement: 20-21 HD (Huge)
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 3 negative levels: the saving throw to remove the negative level is 24. A successful Reflex save (DC 24) 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.