Juiblex, the Faceless Lord (CR 19)

Large Outsider (Chaotic, Evil, Extraplanar, and Tanar'ri)
Alignment: Chaotic evil
Initiative: +6(+2 Dex, +4 Improved Initiative); Senses: blindsight 120 ft., darkvision 60 ft., true seeing, Listen +30, and Spot +30
Languages: Abyssal, Common; telepathy 300 ft.

AC: 31 (-1 size, +2 Dex, +20 natural), touch 11, flat-footed 29
Hit Dice: 21d8+252 (346 hp); DR: 20/cold iron and good
Fort +24, Ref +14, Will +20
Speed: 30 ft. and Climb 30 ft.
Space: 10 ft.; Reach 10 ft.
Base Attack +21; Grapple +35
Attack: Melee: 4 slams +30
Damage: Slam 2d6+10 plus 2d6 acid
Special Attacks/Actions: create slime, summon ooze, summon tanarri
Attack Options: Combat Expertise, Improved Trip, improved grab, constrict 2d6+10 plus 2d6 acid, dissolve, engulf
Abilities: Str 30, Dex 14, Con 34, Int 22, Wis 22, Cha 18
Special Qualities: amorphous, ooze traits, tanarri traits; immune to bludgeoning damage; Immunities: acid, bludgeoning damage, cold, electricity, ooze traits Resist fire 10; SR 30
Feats: Combat Expertise, Combat Reflexes, Dark Speech, Improved Critical (slam), Improved Initiative, Improved Trip, Iron Will, Quicken Spell-Like Ability (hold monster),
Skills: Bluff +28, Concentration +36, Diplomacy +6, Hide +22, Intimidate +30, Knowledge (arcana) +30, Knowledge (dungeoneering) +30, Knowledge (religion) +30, Listen +30, Move Silently +26, Search +30, Sense Motive +30, Spellcraft +32, Spot +30, and Swim +34
Advancement: -
Climate/Terrain: The Abyss (Layer 222)
Organization: Solitary
Treasure/Possessions: Quad standard

Source: Book of Vile Darkness
Fiendish Codex I

Chaotic Subtype

A subtype usually applied only to outsiders native to the chaotic-aligned Outer Planes. Most creatures that have this subtype also have chaotic alignments; however, if their alignments change they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature has a chaotic alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the chaotic subtype overcomes damage reduction as if its natural weapons and any weapons it wields were chaotic-aligned (see Damage Reduction).

Evil Subtype

A subtype usually applied only to outsiders native to the evil-aligned Outer Planes. Evil outsiders are also called fiends. Most creatures that have this subtype also have evil alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature has an evil alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the evil subtype overcomes damage reduction as if its natural weapons and any weapons it wields were evil-aligned (see Damage Reduction).

Extraplanar Subtype

A subtype applied to any creature when it is on a plane other than its native plane. A creature that travels the planes can gain or lose this subtype as it goes from plane to plane. This book assumes that encounters with creatures take place on the Material Plane, and every creature whose native plane is not the Material Plane has the extraplanar subtype (but would not have when on its home plane). An extraplanar creatures usually has a home plane mentioned in its description. These home planes are taken from the Great Wheel cosmology of the D&D game (see Chapter 5 of the Dungeon Master's Guide). If your campaign uses a different cosmology, you will need to assign different home planes to extraplanar creatures.

Creatures not labeled as extraplanar are natives of the Material Plane, and they gain the extraplanar subtype if they leave the Material Plane. No creature has the extraplanar subtype when it is on a transitive plane; the transitive planes in the D&D cosmology are the Astral Plane, the Ethereal Plane, and the Plane of Shadow.

Tanarri Subtype

Most demons encountered outside of the Abyss are tanar'ri. The most populous of the demon subtypes, the tanar'ri form the largest and most diverse group of demons. They are the unchallenged masters of the Abyss at this time. The first tanar'ri were forged from the souls of the first humanoids drawn to the Abyss. Most tanar'ri incorporate humanoid features into their forms as a result of their close ties to the mortal realm.

Traits: A tanar'ri possesses the following traits (unless otherwise noted in a creature's entry).