Wurm, Elder, Cave (CR 23)

Huge Dragon
Alignment: Usually lawful neutral
Initiative: +4 (Improved Initiative); Senses: keen senses, Listen +26, and Spot +26
Languages: Draconic (although older wurms learn to speak Druidic, Sylvan, and Elven)

AC: 26 (-2 size, +18 natural), touch 8, flat-footed 26
Hit Dice: 20d12+120 (250 hp)
Fort +18, Ref +12, Will +16
Speed: 40 ft., burrow 40 ft.
Space: 30 ft./10 ft.
Base Attack +20; Grapple +24
Attack: Bite +31 melee, tail slap +28 melee, 2 claws +28 melee
Full Attack: Bite +31 melee, tail slap +28 melee, 2 claws +28 melee
Damage: Bite 2d8+12, tail slap 1d8+6, claw 1d6+6
Special Attacks/Actions: Breath weapon (cone of phosphorous spray 2d8 DC26)
Abilities: Str 34, Dex 19, Con 22, Int 16, Wis 19, Cha 16
Special Qualities: spells (CL 20)
Feats: Cleave; Improved Initiative; Multiattack; Power Attack; Track; Weapon Focus (bite)
Skills: Climb +22*, Hide +7*, Jump +30, Knowledge (nature) +25, Listen +26, Move Silently +18, Spot +26, Survival +22, and Swim +30*
Advancement: Elder wurm 21-27 HD (Huge)
Climate/Terrain: Any underground
Organization: Solitary or pair (1-2)
Treasure/Possessions: Standard

Source: Dragon #296

Breath Weapon: Wurms create special liquids in sacs behind their jaws. Once a wurm uses its breath weapon, it can't use it again for 1d4 rounds. A blast from a breath weapon always leaves from the wurm's mouth and extends in the direction of the wurm's choice. Cave wurms can breathe a cone of phosphorous spray that coats and outlines an opponent in hot, glowing yellow goop. Creatures in the area are outlined in the phosphorous light, shedding light as candles. They do not benefit from concealment caused by darkness, blur, displacement, invisibility or similar effects. In addition, creatures coated by the phosphorus suffer fire damage due to heat each round. Creatures in the area do not receive saving throws to resist or avoid this effect, and it cannot be scraped or washed off. An additional coating of phosphorus does not cause damage while the original coating remains effective. An elder cave wurm's breath weapon does 2d6 fire damage with a duration of 1d8 rounds.

Improved Grab (Ex): To use this ability, the wurm must hit with its tail slap attack. If it gets a hold, it can constrict.

Constrict (Ex): The wurm can coil around its prey to deal its constriction damage plus tail slap damage with a successful grapple check against any creature of equal size or smaller.

Keen Senses (Ex): Wurms see four times as well as a human in low light conditions and twice as well in normal light. They also have darkvision with a range of 60 feet.

Spells: A wurm knows and casts divine spells as a druid as shown below, gaining bonus spells for a high Wisdom score.

Skills*: Wurms have a natural coloration and limited chameleon ability that grants them a +8 racial bonus to Hide checks in their home environment (a forest wurm in a forest). In addition, wurms with a climb or swim speed receive a +8 racial bonus to Climb or Swim skill checks depending on which movement type they have.