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/Possessions: None

Source: Dungeon #111

Burn (Ex): Those bitten by a firesnake must succeed at a DC so Reflex save or catch fire. The flame burns for 1d4 rounds, (see Catching on Fire).

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.

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

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.