Why is that coat rack moving?

Shevarimarr, Cloaker Burner

CR 9                                                                                                                XP: 6,400
Male cloaker sorcerer 7
CN Large aberration
Init +9; Senses darkvision 60 ft.; Perception +14
AC 23, touch 15, flat-footed 17 (+5 Dex, +8 natural, -1 size)
HP 110 (6d8+7d6+59)
Fort +8, Ref +9, Will +13
Defensive Abilities shadow shift

Speed 10 ft., fly 40 ft. (average)
Melee bite +12 (1d6+6), tail slap +7 (1d8+3)
Space 10 ft., Reach 10 ft. (5 ft. with bite)
Special Attacks engulf, moan
Spell-Like Abilities (CL 7th; concentration +13) 9/day—shadowstrike (1d4+3 nonlethal plus dazzled)
Spells Known (CL 7th)
  3rd (5/day)-Deeper Darkness, Suggestion (DC 19), Vampiric Touch
  2nd (8/day)-Alter Self, Darkness, Darkvision, Web (DC 18)
  1st (8/day)-Charm Person (DC 17), Grease (DC 17), Mage Armor, Magic Missile, Ray of Enfeeblement (DC 17), Unseen Servant
  0th-Dancing Lights, Detect Magic, Mage Hand, Message, Open/Close (DC 16), Prestidigitation, Read Magic (Bloodline shadow)
Str 23, Dex 20, Con 19, Int 12, Wis 14, Cha 22
Base Atk +7; CMB +14; CMD 29 (can't be tripped)
Feats Arcane Strike, Combat Casting, Combat Reflexes, Dodge, Eschew Materials, Hover, Improved Initiative, Silent Spell, Skill Focus (Perception)
Skills Acrobatics +5, Disguise +12, Fly +12, Knowledge (religion) +10, Perception +14, Sense Motive +8, Stealth +10
  Racial Modifiers +8 Disguise to appear as a cloak, sheet, manta ray, or similarly shaped object or creature
Languages Dark Folk, Shadowtongue, Undercommon
SQ bloodline arcana (gain bonus on Stealth checks)
Gear amulet of natural armor +1, pink and green sphere ioun stone
Environment  underground
Organization solitary, pair, mob (3-6), or flock (7-12)
Treasure standard
Engulf (Ex) A cloaker can try to wrap a Medium or smaller creature in its body as a standard action. The cloaker attempts a grapple that does not provoke an attack of opportunity. If it wins the grapple check, it establishes a hold and bites the engulfed victim with a +4 bonus on its attack roll. It can still use its whip-like tail to strike at other targets. Attacks that hit an engulfing cloaker deal half their damage to the monster and half to the trapped victim.
Moan (Ex) A cloaker can emit an infrasonic moan as a standard action, with one of four effects. Fear: All creatures in a 30-foot spread must save (Will negates) or become panicked for 2 rounds. Nausea: All creatures in a 30-foot cone must save (Fortitude negates) or fall prone and be nauseated for 1d4+1 rounds. Stupor: A single creature within 30 feet is affected by hold monster for 5 rounds (Will negates). Unnerve: Anyone within a 60-foot spread automatically takes a -2 penalty on attack and damage rolls. Those in the area for more than 6 consecutive rounds must save (Will negates) or enter a trance, helpless until the moaning stops. Cloakers are immune to these sonic, mind-affecting attacks. A creature that successfully saves against the cloaker's fear, nausea, or unnerve moans cannot be affected by that same moan effect from that cloaker for 24 hours. All of the save DCs against a cloaker's moan are DC 15. Save DCs are Charisma-based.
Shadow Shift (Su) When in dim illumination, a cloaker can manipulate shadows as a free action to create one of three effects: blur (lasts 1d4 rounds, self only), mirror image (CL 6th), or silent image (DC 15, CL 6th, save DC is Charisma-based).
This ray-like creature opens a toothy maw and leers with glaring red eyes. Behind it whips a menacing tail of segmented bone.