Dragon, Mist Very Old (CR 17)

Huge Dragon (Aquatic and Water)
Alignment: Always neutral
Initiative: +0; Senses: blindsense 60 ft., darkvision120 ft., low-light vision, and keen senses
Languages: Draconic

AC: 34 (-2 size, +26 natural), touch 8, flat-footed 34
Hit Dice: 27d12+162 (337 hp)
Fort +21, Ref +15, Will +19
Speed: 40 ft., fly 100 ft.(average), swim 60 ft.
Space: 20 ft./10 ft.
Base Attack +27; Grapple +45
Attack: 1 bite +35, 2 claws +30, 2 wings +30, 1 tail slap +30, 1 crush +30, 1 tail sweep +30
Full Attack: 1 bite +35, 2 claws +30, 2 wings +30, 1 tail slap +30, 1 crush +30, 1 tail sweep +30
Damage: 1 bite 2d8+10, 2 claws 2d6+5, 2 wings 1d8, 1 tail slap 2d6, 1 crush 2d8, 1 tail sweep -
Special Attacks/Actions: Breath weapon 10d6 (29)
Abilities: Str 31, Dex 10, Con 23, Int 18, Wis 19, Cha 18
Special Qualities: Water subtype, immune to acid and fire, mist form, SR 23, CL 13th
Feats: #Feats: 10
Class Skills: Bluff, Sense Motive, Skill points: 114, Survival, and Swim
Advancement: 28-29 HD (Huge)
Climate/Terrain: Temperate and warm aquatic, forest, and 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: Dragons of Faerûn

Breath Weapon (Su): Mist dragons have two types of breath weapons: a cone of scalding steam that deals fire damage and a line of caustic slime. Creatures struck by slime must make Fortitude saves or be sickened for 1d6 rounds plus 1 round per age category of the dragon.

Mist Form (Su): At will as a standard action, a mist dragon can assume a misty form. This power works just like a gaseous form spell cast by a character of the dragon's age category or caster level (whichever is higher), except as follows: The dragon loses its natural armor bonus, but gains a deflection bonus to AC equal to twice its age category. While in mist form the dragon is indistinguishable from mist or fog and gains total concealment when in any kind of natural or magical fog or mist. The dragon gains damage reduction 10/magic, or, if the dragon is old enough to have damage reduction already, its damage reduction increases by 10 points. The dragon can fly at half its normal flying speed, with perfect maneuverability. The dragon cannot use its natural weaponry or breath weapon, but it can use its spell-like abilities and spells. The dragon can dismiss the effect as a standard action.

Spell-Like Abilities: 3/day -- fog cloud, gust of wind, sleet storm, wind wall; 1/day -- control water, control weather, solid fog.

Skills: These skills are available to mist dragons at 1 skill point per rank: Bluff, Sense Motive, Swim, and Survival. These are in addition to the skills noted in the dragon entry on the Monster Manual.

Aquatic Subtype

Creatures with the aquatic subtype always have swim speeds and thus can move in water without making Swim checks. An aquatic creature can breathe underwater. It cannot also breathe air unless it has the amphibious special quality.

Water Subtype

This subtype usually is used for elementals and outsiders with a connection to the Elemental Plane of Water. Creatures with the water subtype always have swim speeds and can move in water without making Swim checks. A water creature can breathe underwater and usually can breathe air as well.