Wurm, Elder, Lava (CR 23)
Huge Dragon (Fire)
Alignment: Usually neutral evil
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: 20 ft., swim 20 ft., burrow 20 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 (line of molten rock 10d6/4d6 DC26)
Abilities: Str 34, Dex 19, Con 22, Int 16, Wis 19, Cha 16
Special Qualities: spells (CL 20), fire subtype
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 mountains and underground (volcanic)
Organization: Solitary or pair (1-2)
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. A lava wurm can spray a line of molten rock that causes both fire (6d6) and impact (3d6) damage to all creatures in the area (Reflex save for half).
Fire Subtype (Ex): Fire immunity; double damage from cold except on a successful save.
Lava Walk (Ex): A lava wurm is as sure-footed on slow-flowing lava as in dry conditions and never needs to make a Balance check to move on lava during normal conditions.
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.
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.