Protean, Amalgessi
This serpentine creature has three snake-like heads sprouting from a mass of serpent coils.

Amalgessi (CR 8; XP 4,800)
CN Medium outsider (chaotic, extraplanar, protean, shapechanger)
Init +9; Senses blindsense 30 ft., darkvision 60 ft., detect law; Perception +16
AC 21, touch 15, flat-footed 16
(+5 Dex, +6 natural)
hp 104 (11d10+44)
Fort +11, Ref +14, Will +5
DR 5/Law; Defensive Abilities amorphous anatomy, freedom of movement; Immune acid, polymorph; Resist electricity 10, sonic 10; SR 19
Speed 30 ft., fly 30 ft. (perfect), swim 30 ft.
Melee 3 bites +17 (1d6+4/19-20 plus elemental bite), or tail slap +11 (1d6+2 plus coruscating burst)
Space 5 ft.; Reach 5 ft. (10 ft. with bite)
Special Attacks coruscating burst, elemental bite
Spell-Like Abilities (CL 8th; concentration +11)
Constant—detect law
At will—acid arrow, blink, dimension door (self plus 50 lbs. of objects only), fire shield
1/day—ethereal jaunt, protection from energy
Str 19, Dex 21, Con 18, Int 11, Wis 14, Cha 16
Base Atk +11; CMB +15; CMD 30 (can’t be tripped)
Feats Combat Reflexes, Improved Critical (bite), Improved Initiative, Lightning Reflexes, Weapon Finesse, Weapon Focus (bite)
Skills Acrobatics +19, Fly +27, Perception +16, Sense Motive +16, Stealth +19, Swim +23
Languages Abyssal, Protean
SQ change shape (greater polymorph)
Environment planes (Realms Beyond)
Organization solitary
Treasure standard
Special Abilities
Elemental Bite (Ex) The amalgessi’s trio of heads crackle with errant bursts of potential elemental energies. Each successful bite causes an additional 1d6 damage of whatever element the protean chooses (acid, fire, electricity, or sonic). A successful critical hit triples the elemental
damage inflicted.
Coruscating Burst (Su) The amalgessi’s tail flickers with a dangerous corona of raw potential energy. Upon striking a target, this energy detonates, dealing 4d6 elemental damage of its choice (acid, fire, electricity, or sonic) to the creature struck, as well as 2d6 damage to any other creatures within 10 feet of them. This damage lingers, continuing to do 2d6 damage to the primary target and 1d6 damage to others on the next round, and finally 1d6 to the primary target only on the final round before fully dissipating.

Solitary hunters prowling through the Outer Realms, the chaos wyrms known as amalgessi are a curious variety of the protean species, with a marked affinity for the Elements. Comfortable in the Realms Within, Between and Beyond, their shifting forms resemble a mass of ethereal knots comprising a tangle of coils, all emitting a flickering storm of errant elemental energies. Amalgessi are capable of manipulating and unleashing this energy on their enemies, in impressive but typically unpredictable displays.

In combat, amalgessi are able to slide in and out of their current dimension, into the Ethereal Plane and back again, making them tricky and cunning opponents. When encountered, amalgessi will attack beings that exhibit elemental natures, powers, items of appearance, sometimes negotiating to find those who do- or just wading into combat on a whim. They are rarely found with other proteans, unless a powerful leader is present.

On Porphyra
Rarely seen on the Material plane, the amalgessi never existed prior to the NewGod Wars. Though none of the widely known members of the Slithering Symphony lay claim to their creation, they bear the bizarre aesthetics of Y’Tinasni the Inchoate Exultation, the Lady of Madness. Even if true however, the amalgessi seem almost more at home in the Realms Within and Between than in listening to the distant mad whispers of their creator. Cavorting in places where the elements mix and come into conflict, the amalgessi only follow the orders of greater proteans with a certain level of lackadaisical care, preferring to spend their time harassing elemental creatures, something which they did en masse against the genies and their armies during the NewGod Wars, especially those in thrall to Qarryn and Drothos.