Firesnake (CR 1/2)

Small Elemental (Fire)
Alignment: Always neutral
Initiative: +2 (Dex); Senses: Listen +6 and Spot +6

AC: 16 (+1 size, +2 Dex, +3 natural), touch 13, flat-footed 14
Hit Dice: 1d8 (4 hp)
Fort +0, Ref +4, Will +1
Speed: 20 ft., climb 20 ft.
Space: 5 ft./5 ft.
Base Attack +0; Grapple -5
Attack: Bite +3 melee
Full Attack: Bite +3 melee
Damage: Bite 1d3-1
Special Attacks/Actions: Burn
Abilities: Str 8, Dex 15, Con 15, Int 1, Wis 12, Cha 2
Special Qualities: Elemental traits, provides shadowy illumination
Feats: Dodge; Weapon Finesse
Skills: Balance +11, Climb +11, Hide +6, Listen +6, and Spot +6
Advancement: -
Climate/Terrain: Elemental Plane of Fire
Organization: Solitary
Treasure: None

Source: Dungeon #111


Firesnake bites don't do much damage directly, but they sometimes light the target on fire.

Burn (Ex): Those bitten by a firesnake must succeed at a DC so Reflex save or catch fire. The flame burns for 1d4 rounds, as described in the Catching on Fire section of the DUNGEON MASTER'S Guide (page 303).

Skills: Firesnakes have a +4 racial bonus on Listen and Spot checks and a +8 racial bonus on Balance and Climb checks. They use their Dexterity modifier for Climb checks.

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.