Immoth (CR 9)
AC: 18 (-1 size, +3 Dex, +6 natural), touch 12, flat-footed 15
Hit Dice: 10d8+40 (85 hp); DR: 5/magic bludgeoning
Fort +11, Ref +10, Will +4
Speed: 30 ft., fly 30 ft. (perfect), swim 30 ft.
Space: 10 ft./10 ft.
Base Attack +7; Grapple +15
Attack: Claw +10 melee (1d4+4 plus 1d6 cold)
Full Attack: 2 claws +10 melee (1d4+4 plus 1d6 cold) and tail slap +5 melee (1d6+2 plus 1d6 cold plus poison)
Special Attacks/Actions: Ice runes, poison, spells
Abilities: Str 18, Dex 16, Con 19, Int 14, Wis 13, Cha 21
Special Qualities: Cold subtype, elemental traits, icewalking, immunities, SR 23
Feats: Cleave; Combat Casting; Combat Reflexes; Power Attack
Skills: Climb +17, Hide +12, Jump +17, Spot +14, and Swim +12
Advancement: By character class
Climate/Terrain: Any cold
Monster Manual II
Before wading into battle, an immoth casts spells designed to bolster its physical and defensive capabilities. In melee, it immobilizes as many foes as possible with its tail poison and uses rune magic to overcome any serious threats. Most immoths prefer runes that inflict pain or can debilitate opponents. When seriously threatened, these monsters flee by walking up the nearest icy cliff. Then, from on high, they cast damaging spells to deter foes from following.
Ice Runes (Sp): Any spell an immoth has prepared can be inscribed on an ice nugget. The creature can trigger the spell contained in such an ice rune as a free action. An ice rune remains magical until triggered by the immoth. Each immoth has at least 3d4+2 ice runes embedded on its body. Some wonder whether this ability lends credence to the story about frozen words in the Mountain of Ultimate Winter.
Poison (Ex): An immoth delivers its freezing venom (Fortitude save DC 19) with each successful tail attack. The initial damage is paralysis (1d6+2 rounds), and the secondary damage is 1 point of Intelligence drain per round of paralysis.
Spells: An immoth can cast arcane spells as a 12th-level sorcerer (spells/day 6/8/7/7/7/6/3; spells known 9/5/5/4/3/2/1; save DC 15 + spell level). It cannot cast spells with the fire descriptor.
Cold Subtype (Ex): An immoth is immune to cold damage but takes double damage from fire unless a saving throw for half damage is allowed. In that case, the creature takes half damage on a success and double damage on a failure.
Icewalking (Ex): This ability works like the spider climb spell, except that it applies to all icy surfaces and it is always active.
Immunities (Ex): Because of its dense crystalline body, an immoth takes only half damage from piercing and slashing weapons.
This subtype usually is used for elementals and outsiders with a connection to the Elemental Plane Air. Air creatures always have fly speeds and usually have perfect maneuverability (see the section on Movement).
A creature with the cold subtype has immunity to cold. It has vulnerability to fire, which means it takes half again as much (+50%) damage as normal from fire, regardless of whether a saving throw is allowed, or if the save is a success or failure.
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.