Dragon, Mercury Great Wyrm (CR 18)
AC: 41 (-2 size, +29 natural, +4 Dex), touch 12, flat-footed 37
Hit Dice: 30d12+180 (375 hp); DR: 15/magic
Fort +23, Ref +21, Will +21
Speed: 60 ft., fly 200 ft. (poor)
Space: 20 ft./10 ft.
Base Attack +30; Grapple +49
Attack: 1 bite +47, 2 claws +42, 2 wings +42, 1 tail slap +42, 1 crush +42, 1 tail sweep +42
Full Attack: 1 bite +47, 2 claws +42, 2 wings +42, 1 tail slap +42, 1 crush +42, 1 tail sweep +42
Damage: 1 bite 2d8+11, 2 claws 2d6+5, 2 wings 1d8, 1 tail slap 2d6, 1 crush 2d8
Special Attacks/Actions: Breath weapon 10d8 (31)
Abilities: Str 33, Dex 18, Con 23, Int 18, Wis 19, Cha 18
Special Qualities: Fire subtype, brilliance, gaze screen, mirror image, Alternate form, telekinesisFear Aura DC 29
Feats: #Feats: 11
Class Skills: Balance, Escape Artist, Jump, Skill points: 126, and Tumble
Advancement: 31-32 HD (Huge)
Climate/Terrain: Temperate and warm mountain and underground
Organization: Solitary, pair, or family (1-2 and 2-5 offspring)
Treasure/Possessions: Triple standard
Dragons of Faerûn
Breath Weapon (Su): A mercury dragon's breath weapon is a line of intense light that burns whatever it touches, dealing fire damage.
Brilliance (Ex): As a standard action, a mercury dragon can use the mirror-bright membranes of its wings to reflect and concentrate available light into a beam of dazzling brightness. To use this power, the dragon needs light as bright as an overcast day or clear, moonlight night. Torchlight or candle light is insufficient.
The power creates a thin beam the dragon can aim at a single target within 30 feet per age category of the dragon. The target is blinded for 1d4+1 rounds unless it makes a Reflex save (DC 10 + 1/2 the dragon's Hit Dice, + the dragon's Dexterity modifier). If not using this technique as a weapon, the dragon can create a cone of light as bright as a daylight spell up to 60 feet long per age category of the dragon. The cone lasts 3 rounds.
Alternate Form (Su): A mercury dragon of adult age or older can assume any animal or humanoid form of Medium size or smaller as a standard action three times a day. This ability functions as a polymorph spell cast on itself at its caster level, except that the dragon does not regain hit points for changing form and can assume only the form of an animal or humanoid. The dragon can remain in its animal or humanoid form until it chooses to assume a new one or return to its normal form.
Fire Subtype (Ex): Fire immunity, +50% damage from cold.
Protected Sight (Ex): A mercury dragon is immune to any effect that would blind or dazzle it. It also gains +3 racial bonus on saving throws against any light or pattern effect.
Spell-Like Abilities: At will -- gaze screen*; 3/day -- mirror image; 2/day -- telekinesis; 1/day -- project image.
Skills: These skills are available to mercury dragons at 1 skill point per rank: Bluff, Disguise, Sense Motive, and Survival. Mercury dragons have the Jump skill for free at 1 rank per Hit Die. These are in addition to the skills noted in the dragon entry in the Monster Manual.
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.