This towering, three-tailed, six-eyed beast seems like three rune-backed serpents partially melded together into one body.
CR 15 XP 51,200 CE Gargantuan outsider (chaotic, evil, extraplanar) Init +9; Senses arcane sight, darkvision 120 ft., detect good, low-light vision, scent, true seeing; Perception +29
AC 31, touch 12, flat-footed 25 (+5 Dex, +1 dodge, +19 natural, –4 size) hp 210 (20d10+100) Fort +17, Ref +13, Will +20 DR 10/good; Immune electricity, poison; Resist acid 10, cold 10, fire 10; SR 26
Speed 40 ft., climb 20 ft. Melee bite +25 (3d8+9 plus poison), 3 tail slaps +20 (2d8+4 plus grab) Space 20 ft.; Reach 15 ft. Special Attacks constrict (2d6+9), redirect spell Spell-Like Abilities (CL 18th; concentration +25)
Constant—arcane sight, detect good, true seeing At will—detect thoughts (DC 19), greater teleport (self plus 50 lbs. of objects only), invisibility, suggestion (DC 20) 3/day—charm monster (DC 21), mass suggestion (DC 23), scrying (DC 21), symbol of pain (DC 22), touch of idiocy, vision 1/day—summon (level 5, 1 hezrou or 1d4 succubi, 50%)
Str 29, Dex 21, Con 21, Int 26, Wis 22, Cha 24 Base Atk +20; CMB +33 (+37 grapple); CMD 49 (can’t be tripped) Feats Combat Reflexes, Dodge, Improved Initiative, Improved Iron Will, Improved Vital Strike, Iron Will, Lightning Reflexes, Mobility, Spring Attack, Vital Strike Skills Acrobatics +25 (+29 jump), Bluff +30, Climb +17, Diplomacy +27, Disguise +27, Intimidate +27, Knowledge (arcana) +31, Knowledge (any two) +31, Linguistics +28, Perception +29, Sense Motive +29, Spellcraft +31, Stealth +16, Use Magic Device +27 Languages Abyssal, Common, Draconic; telepathy 100 ft. SQ change shape (any humanoid as a swift action, but always retains one serpentine trait that negates the bonus to Disguise checks; alter self)
Redirect Spell (Su) Any creature that attempts to cast a spell within 30 feet of a xacarba must cast the spell defensively. If the caster fails the concentration check to do so (or if the caster opts to not cast defensively), the xacarba can choose the target of the spell as a immediate action. The new target must be a legal target—if there’s no legal alternative target to choose from, this ability cannot be used. Fiends hailing from the darkest reaches of the Abyss, xacarbas are manipulation and destruction intertwined. With their infamous ability to redirect spells, these serpentine goliaths wreak havoc on the mind as well as the body, turning allies against one another and reveling in the destruction doing so produces.