Marilith (CR 17)

Large Outsider (Chaotic, Extraplanar, Evil, and Tanar'ri)
Alignment: Always chaotic evil
Initiative: +4 (Dex); Senses: darkvision 60 ft., Listen +31, and Spot +31
Languages: Telepathy 100 ft.

AC: 29 (-1 size, +4 Dex, +16 natural), touch 13, flat-footed 25
Hit Dice: 16d8+144 (216 hp); DR: 10/good and cold iron
Fort +19, Ref +14, Will +14
Speed: 40 ft.
Space: 10 ft./10 ft.
Base Attack +16; Grapple +29
Attack: Longsword +25 melee or slam +24 melee or tail slap +24 melee
Full Attack: Primary longsword +25/+20/+15/+10 melee, and 5 longswords +25 melee and tail slap +22 melee; or 6 slams +24 melee and tail slap +22 melee
Damage: Primary longsword 2d6+9/19-20, longswords 2d6+4/19-20, slam 1d8+9, tail slap 4d6+4
Special Attacks/Actions: Spell-like abilities, improved grab, constrict 4d6+13, summon Tanarri
Abilities: Str 29, Dex 19, Con 29, Int 18, Wis 18, Cha 24
Special Qualities: immunity to electricity and poison, resistance to acid 10, cold 10, and fire 10, SR 25
Feats: Combat Expertise; Combat Reflexes; Multiattack; Multiweapon Fighting; Power Attack; Weapon Focus (longsword)
Skills: Bluff +26, Concentration +28, Diplomacy +30, Disguise +7 (+9 acting), Hide +19, Intimidate +28, Listen +31, Move Silently +23, Search +23, Sense Motive +23, Spellcraft +23 (+25 scrolls), Spot +31, Survival +4 (+6 following tracks), and Use Magic Device +26 (+28 scrolls)
Advancement: 17-20 HD (Large); 21-48 HD (Huge)
Climate/Terrain: Infinite Layers of the Abyss
Organization: Solitary or pair
Treasure/Possessions: Standard coins, double goods, standard items plus 1d4 magic weapons

Source: Monster Manual

Spell-Like Abilities: At will - animate dead, bestow curse, chaos hammer, cloudkill, comprehend languages, darkness, desecrate, detect good, detect law, detect magic, inflict serious wounds, magic circle against good (self only), magic weapon, project image, pyrotechnics, see invisibility shatter telekinesis, teleport without error (self plus 50 pounds of objects only), unholy aura, and unholy blight. These abilities are as the spells cast by a 13th-level sorcerer (save DC 13 + spell level).

Improved Grab (Ex): To use this ability, the marilith must hit a Medium-size or smaller opponent with its tail slam attack. If it succeeds, it can constrict.

Constrict (Ex): A marilith deals 4d6+7 points of damage with a successful grapple check against Medium-size or smaller creatures. The constricted creature must succeed at a Fortitude save (DC 19) or lose consciousness for at long as it remains in the coils and for 2d4 rounds thereafter.

Summon Tanar'ri (Sp): Once per day a marilith can attempt to summon 4d10 dretches, 1d4 hezrou, or one nalfeshnee with a 50% chance of success, or one glabrezu or another marilith with a 20% chance of success.

Skills: Mariliths receive a +8 racial bonus to Listen and Spot checks.

Feats: A marilith receives the Multidexterity and Multi-weapon Fighting feats as bonus feats. In combination with its natural abilities, these feats allow the marilith to attack with all its arms at no penalty.

Tanar'ri Traits: Tanar'ri are immune to poison and electricity. It has cold, fire, and acid resistance 20. Tanar'ri can communicate telepathically with any creature within 100 feet that has a language.

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).

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.

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).

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).