I'm surprised something like this hasn't been put in a book yet, as its a classic concept.
Dimunitive Fey (cold, swarm)
Hit Dice: 8d6+24 (52 hp)
Speed: 10 ft. (2 squares), fly 40 ft. (good)
Armor Class: 28 (+8 armor, +6 dex, +4 size), touch 2-, flat-footed 22
Base Attack/Grapple: +4/-
Attack: Swarm (2d6+1 plus 1d4 frostburn plus shivering touch)
Full Attack: Swarm (2d6+1 plus 1d4 frostburn plus shivering touch)
Space/Reach: 10 ft./-
Special Attacks: Distraction, shivering touch, spell-like abilities
Special Qualities: Blue skin, immunity to weapon damage, low-light vision, religious repel, skate, swarm traits, vulnerability to fire
Saves: Fort +7, Ref +12, Will +7
Abilities: Str 5, Dex 22, Con 16, Int 17, Wis 12, Cha 16
Skills: Balance +17, Concentration +14, Craft (ice pictures) +18, Hide +29, Listen +12, Open Lock +17, Perform (dance) +18, Sense Motive +12, Spot +12
Feats: Cold Focus
, Improved Initiative, Great Fortitude, Weapon Finesse(B)
Environment: Any temperate or cold land
Challenge Rating: 7
Alignment: Usually neutral
Level Adjustment: -
Individual frosti appear as tiny elves of both genders of astonishing beauty with the palest of white skin and long silver tresses. Their eyes so blue as to be purple with no trace of pupil. Their feet are quite strange, with a single claw protruding from the front of their foot and curving down below and extending past the heel with a razor sharp edge like an ice skate. From their fingers grow long talons. Though they possess no obvious wings, their slight forms are constantly adrift in a nipping wind that takes them hither and thither at their whim.
Frosti are a strange people who live through the warmer seasons deep within caves or other cool locales in a state of hibernation until a nip in the air awakens them from their slumber. They tend to remain hidden during the day and come out at night to dance within the bitter air and to weave beautiful patterns of ice upon window panes and other surfaces. They love little tricks such as coating steps with ice or causing the falling snows to build up in inconvenient areas, their laughter sounding like the chiming of tiny bells at their victim's ire.
Strangely though frostis have a distaste and fear of churches and the priests and clerics that occupy them, keeping well away from them when at all possible. The hanging of holly and wreathes in particular infuriates them so that households who put one up are often the most visited targets of their mischief.
Frosti speak common and fey.
Frosti, though mischievous, are not very combative creatures, though they are quick to anger if threatened. They then try to surround their provocateur, pricking the skin mercilessly with their claws as they dance upon it until it lies in uncontrollable shivering upon the ground.
Blue Skin (Su):
When in danger a frosti can freeze the moisture out of the air to surround his body in an intensely tough yet strangely flexible suit of armor as a standard action. This acts as full plate armor though does not impose any penalties. This suit melts within 1d4 rounds in temperatures above freezing. If exposed to flame or an attack that deals fire damage it vaporizes, though remains in tact long enough to protect against the attack that melted it.
As well, their claws gain a layer of super fine blue ice that grants a +1 bonus to all damage rolls.
Any living creature vulnerable to a frosti's damage that begins its turn with the swarm in its square is nauseated for 1 round; a Fortitude save (DC 15) negates the effect. Spellcasting or concentrating on spells within the area of a swarm requires a Concentration check (DC 20 + spell level). Using skills that involve patience and concentration requires a DC 20 Concentration check.
Religious Repel (Ex):
Frostis recoil from a strongly presented holy or unholy symbol. A frosti must stay at least 5 feet away from a creature holding a holy symbol and cannot touch or make melee attacks against the creature holding the item for the rest of the encounter.
Shivering Touch (Sp):
Whenever a victim takes frostburn damage from a frosti swarm they take 1d6 dexterity damage as they go into a fit of intense shivering.
While on a slippery surface a frosti's land speed increases by 20 feet.
At will - Crunchy Snow, Glaze Lock, Ice Slick, Snowdrift; 3/day - Control Winds, Flash-Freeze, Icicle; 1/day Hibernal Healing. Caster level 8th. Save DC's are Charisma-based.
Frosti have a +4 racial bonus on Craft and Perform checks.