This towering, three-tailed, six-eyed beast seems like three rune-backed serpents partially melded together into one body.
Xacarba CR 15
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
Speed 40 ft., climb 20 ft.
Space 20 ft.; Reach 15 ft.
Special Attacks constrict (2d6+9), redirect spell
Spell-Like Abilities (CL 18th; concentration +25)
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)
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.
Environment any land (Abyss)
Poison (Su) Bite—injury; save Fort DC 25; frequency 1/round for 6 rounds; effect one chosen by the xacarba from three options; cure 2 consecutive saves. The save DC is Constitution-based.
Fiendish Bile: effect 1d4 Str damage (good-aligned creatures also take 2d8 points of damage).
Mysterious Blood: effect 1d4 Dex and 1d4 Wis damage plus confusion for 1 round.
Vile Disjunction: effect targeted greater dispel magic (CL 18th) on the creature.
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.