Rokan - evil, bat-winged, serpent spell-caster (Anti-Coatl)

My inspiration for the Rokan is to be an evil Coatl - a direct threat, not one hiding in the corners inspiring or teaching, but one that is very active in completing its goals. This is a winged serpent creature that uses magic in devious ways, but it has two aspects, as they can switch to a larger, spell-less figure in physical combat. They join evil groups to learn forbidden magic and gain access to magical nexus sites but will not hesitate to flee if a battle turns against them or the organization.

Rokan

Small Size Magical Beast
Hit Dice: 82 hp (11d8 + 33 con)
Initiative: +9 (small), +2 (Large)

Speed: (when small) 20 ft, Fly 60 (Good); 40 ft (Cannot fly when large sized)
AC: 24 (+8 natural, +1 size, +5 Dex), touch 17, flat-footed 18
Base Attack/Grapple: +3/+10 (Large form only)
Attack: Bite+11 (2d6+5) (Large Size only)
Special Attack: Grapple +15 (3d6) (Large Size only)
2nd Special Attack: Back Slap +10 (2d8+5)
Base Atk +12 CMB +10 CMD 25 (Small)

Special Attacks: Spells as 12th level Sorcerer (Small Size Only), Turn Undead as 8th level evil Cleric
Special Qualities: Change to Large Size; +15 Constrict 2d8 (Grapple)
Saves: Fort +10 Ref +12 (+8 when large) Will +3

Abilities: Str 11, Con 16, Dex 21, Int 16, Wis 10, Cha 20 *Switch Str and Dex scores when they change to large size

Skills: Diplomacy, +12, Knowledge (Arcana) +9, Knowledge (Planes) +9, Perception +12, Move Silently +9, Sense Motive +9, Spellcraft +12, (Escape Artist +20 in small size)
Feats: Eschew Spell Component, Hover, Improved Initiative, Imp Evasion

Environment: Magical Nexi or Evil Temples
Organization: Solitary
Challenge Rating: 12

Treasure: Double Standard
Alignment: Neutral Evil
Advancement: by character class (always Sorcerer)

Radiate protection from Good 20 ft radius: Good-aligned characters will suffer a –2 to all of their attacks and saving throws when facing a Rokan.

Aura of Fear: Creatures within 20 ft of a Rokan are affected by a powerful fear effect. Those who fail a will saving throw (DC 18) will suffer the effects of a fear spell. Those who save are not affected. Creatures who pass their saving throw are unaffected by the same Rokan's fear effect for 24 hours.

Large Size: AC 21, Speed 30 ft., climb 30 ft., swim 30 ft;

The Rokan is a dual sized creature, it`s primary form is a small bat-winged, serpent with small spike horns that wields spells. It's larger body is between 15 to 20 feet long and three feet wide - it is very good in combat, especially at constricting victims. They have a rough black skin with small barely noticeable yellow triangles. When they expand to their large size, their wings are absorbed into their body and these yellow scales dominate most of its scales. They will not hesitate to take down foes using either strategy.

They often work for evil organizations for high payments, either as a protector or a spell-casting ally. While not cowards, they have a habit of retreating when combat is going against them or their allies. This gives them a horrible reputation. When the going is smooth, there are few mortal spell-casters as beneficial as a Rokan to have on your side.

Combat: Rokan are superb natural sorcerers with a wide variety of spells and other abilities. They have no pre-set plan, as they try to gauge any situation and react quickly to almost any situation. They switch to their large form to inflict heavy damage or to constrict foes. All spells they cast upon themselves in their small form are retained if they switch size. They radiate a protection from good and fear aura within a 20 ft radius in both forms.

They can control undead as an 8th level evil priest in their small size only. Undead still listen to Rokan who have switched size - but they cannot attempt to turn more undead in their large format. One of their primary motivators is magical treasure, so they are always keen not to destroy magical items, especially those they can actually use.

Typical Spells as 12th level Sorcerer; Spells per Day: 6/6/6/6/6/5/3; Spells Known: 9/5/5/4/3/2/1*
1st level: Shield, Obscuring Mist, Ray of Enfeeblement, Colour Spray, Magic Missile
2nd level: Protection from Arrows, Glitterdust, Mirror Image, Blindness, Levitate
3rd level: Dispel Magic, Lightning Bolt, Gaseous Form, Vampiric Touch
4th level: Shout, Bestow Curse, Stoneskin
5th level: Dismissal, Feeblemind
6th level: Disintegrate (item only)

Set Form: Rokan never use magic that manipulates their fform, they take a -8 on skill or spell checks if forced into an alternate form.