After getting a few requests Rob Manning took some time to create a statblock for Mother Murrell's cat an NPC from

Tansy appears as Mother Murrell's pet cat until her mistress attacks. The chaos beast then transforms into a snarling whirlwind of claws and teeth; spiraling in a mini-tornado, complete with lightning flashes. Mother Murrell's deity gifted the sorceress with Tansy to protect her in her research. A few of Tansy's victims still wander under the Evocative City; and though none of the spawn are blessed with her electrical powers, some have grown to colossal proportions.
Tansy of Bedlam Asylum CR 9
XP 6,400
thunder child chaos beast
CN medium elemental (extraplanar, air)
Init +5; Senses: Perception +11
Defenses
AC 22 (+3 Dex., +5 natural, +4 dodge), touch 17, flat-footed 15
hp 44 (8d8+4)
Fort +7, Ref +11, Will +7
Offense
Speed 40 ft.
Melee
claw +10 (1d3+2 plus corporeal instability plus 1d6 electricity)
Special Attacks
Corporeal Instability, Breath Weapon, Electric Aura, Electric Grapple
3/day—fog cloud, gaseous form, sound burst
Statistics
Str 14, Dex 18, Con 13, Int 12, Wis 12, Cha 10
Base Atk +8; CMB +4; CMD 13
Feats Dodge, Improved Initiative, Lightning Reflexes, Mobility
Skills Acrobatics +14, Climb +12, Escape Artist +14, Perception +11, Stealth +13, Survival +11
Special Qualities
Cloud Sight, Lightning Jump
Special Abilities
Corporeal Instability (Su) A blow from a chaos beast against a living creature can cause a terrible transformation. The creature must succeed on a DC 15 Fortitude save or become a spongy, amorphous mass. Unless the victim manages to control the effect (see below), its shape melts, flows, writhes, and boils. The save DC is Constitution-based.
An affected creature is unable to hold or use any item. Clothing, armor, rings, and helmets become useless. Large items worn or carried—armor, backpacks, even shirts—hamper more than help, reducing the victim’s Dexterity score by 4. Soft or misshapen feet and legs reduce speed to 10 feet or one-quarter normal, whichever is less. Searing pain courses along the nerves, so strong that the victim cannot act coherently. The victim cannot cast spells or use magic items, and it attacks blindly, unable to distinguish friend from foe (-4 penalty on attack rolls and a 50% miss chance, regardless of the attack roll).
Each round the victim spends in an amorphous state causes 1 point of Wisdom drain from mental shock. If the victim’s Wisdom score falls to 0, it becomes a chaos beast.
A victim can regain its own shape by taking a standard action to attempt a DC 15 Charisma check. A success reestablishes the creature’s normal form for 1 minute. On a failure, the victim can still repeat this check each round until successful.
Immunity to Transformation (Ex) No mortal magic can permanently affect or fix a chaos beast’s form. Effects such as polymorphing or petrification force the creature into a new shape, but at the start of its next turn it immediately returns to its mutable form as a free action.
Breath Weapon (Ex): Once every 1d4 rounds, 3d6 points of electricity damage, 5-foot-wide line of lightning 130 feet long or 10-feet-wide and 65 feet long, Reflex save DC 14 halves the damage.
Electric Aura (Ex): A thunder child emits an aura of electricity that can wound nearby creatures. Any creature within 10 feet of a thunder child must succeed on a Reflex save DC 14 each round that it remains within range or take 1d6 points of electricity damage. A thunder child can suppress or resume the use of this ability as a free action.
Electric Grapple (Ex): Any creature grappling a thunder child takes 2d6 points of electricity damage each round that the grapple is maintained.
Cloud Sight (Ex): A thunder child can see through clouds, gases, fogs, mists, and smoke as though they didn’t inhibit vision. Creatures and objects do not gain concealment from a thunder child due to such conditions. A thunder child may use this ability while gaseous.
Lightning Jump (Ex): When a thunder child breathes lightning, it may teleport with no chance of error to any location within the area of the lightning attack as a free action. It must make this jump immediately after using its breath weapon.


Is this the Thunder Child Template from Green Ronin's Advanced Bestiary?
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