Wolf, Magma (CR 4)

Medium Magical Beast (Fire)
Alignment: Always chaotic evil
Initiative: +2 (Dex); Senses: Listen +7 and Spot +4

AC: 15 (+2 Dex, +3 natural), touch 12, flat-footed 13
Hit Dice: 4d10+12 (34 hp)
Fort +7, Ref +6, Will +1
Speed: 50 ft., burrow 20 ft.
Space: 10 ft./5 ft.
Base Attack +4; Grapple -1
Attack: Bite +7 melee
Full Attack: Bite +7 melee
Damage: Bite 1d6+4 and combustion
Special Attacks/Actions: Combustion
Abilities: Str 17, Dex 15, Con 16, Int 7, Wis 11, Cha 10
Special Qualities: Fire subtype
Feats: Power Attack
Skills: Listen +7, Spot +4, and Survival +6
Advancement: 5-6 HD (Medium-size); 7-12 HD (Large)
Climate/Terrain: Temperate and warm land and underground
Organization: Solitary, pair, or pack (2-12)
Treasure/Possessions: None

Source: Dragon #293

Combustion (Ex): Anyone a magma wolf touches must succeed at a Reflex save (DC 12) or take an additional 2d8 points of fire damage as clothes ignite or armor becomes searing hot. The damage continues for an additional 1d4+2 rounds after the magma wolf's last successful attack. Magma wolves can also ignite flammable materials with a touch.

Fire Subtype: Immune to fire damage; takes double damage from cold unless a saving throw for half damage is allowed, in which case it takes half damage on a success and double damage on a failure.

Magma wolves try to get into melee as quickly as possible, so their natural heat can burn their opponents. If they are in terrain that can catch fire, they try to create fires around their opponents before moving in to attack.

Fire Subtype

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.