Centipede, Least Spirit (CR 1/2)

Diminutive Outsider (Spirit)
Alignment: Always neutral
Initiative: +4 (Dex)

AC: 19 (+4 size, +4 Dex, +1 natural), touch 18, flat-footed 15
Hit Dice: 1d8+1 (5 hp)
Fort +3, Ref +6, Will +0
Speed: 20 ft. (centipede), 10 ft. (toad)
Space: 1 ft./0 ft.
Base Attack +1; Grapple -13
Attack: Bite +9 melee
Full Attack: Bite +9 melee
Damage: Bite 1d2-2
Special Attacks/Actions: Black fog cloud
Abilities: Str 6, Dex 19, Con 12, Int 5, Wis 6, Cha 5
Special Qualities: Change shape, SR 10, poison immunity
Feats: Weapon Finesse
Skills: Escape Artist +8, Hide +20, Intimidate +1, and Move Silently +8
Advancement: 2 HD (Diminutive)
Climate/Terrain: Warm or temperate land
Organization: Solitary
Treasure/Possessions: None

Source: Oriental Adventures

Black Fog Cloud (Su): A Least Spirit centipede can cough up a poisonous cloud of black fog as a standard action. The cloud extends in a spread centered on the spirit centipede with a radius of 5 feet. A centipede is immune to the effects of its own cloud. Any creature that comes in contact with a black fog cloud must make a Fortitude saving throw (DC 11) or suffer the effects of the cloud. The effects depend on the centipede's current form.

The black fog cloud obscures all sight, including darkvision, beyond 5 feet. Creatures within 5 feet of an enemy have one-half concealment, so attacks from that enemy have a 20% miss chance. Creatures farther away from an enemy have total concealment, imposing a 50% miss chance, and attackers can't use sight to locate the target. Spirit centipedes have no sight advantage within the cloud. A black fog cloud disperses after 1d4 rounds.

Alternate Form (Ex): A least spirit centipede is the smallest variety. It can assume two different forms - centipede and toad. Changing form is a full-round action.

Spirit Subtype

Spirit creatures include some fey and elementals (nature spirits), outsiders (celestial spirits), undead (ghosts and ancestors), and even dragons. Spirit creatures are nor necessarily incorporeal, despite their name - in the worlds of Oriental Adventures, some spirits are as much flesh and bone as humans are. The only game effect of the spirit type modifier is that spirit creatures are all affected by spells such as commune with greater spirit, invisibility to spirits, and protection from spirits.