Orcus, Prince of the Undead (CR 22)

Large Outsider (Chaotic, Evil, Extraplanar, and Tanar'ri)
Alignment: Chaotic evil
Initiative: +10(+6 Dex, +4 Improved Initiative); Senses: darkvision 60 ft., true seeing, Listen +34, and Spot +34
Languages: Abyssal, Common; telepathy 300 ft.

AC: 48 (-1 size, +6 Dex, +28 natural, + 5 deflection), touch 20, flat-footed 42
Hit Dice: 26d8+338 (455 hp); DR: 20/cold iron and good
Fort +28, Ref +21, Will +20
Speed: 20 ft. and Fly 40 ft. (average)
Space: 10 ft.; Reach 10 ft.
Base Attack +26; Grapple +42
Attack: Melee: Wand of Orcus +44/+39/+34/+29 and claw +35 and gore +35 and sting +35
Damage: Wand of Orcus (+6 chaotic unholy greatclub) 10d10+27/19-20, claw 1d6+7, horns 2d6+7, sting 1d3+7 plus poison
Special Attacks/Actions: summon tanarri, summon undead
Abilities: Str 35, Dex 23, Con 37, Int 27, Wis 20, Cha 19
Special Abilities: Spell-Like Abilities (CL 20th): At will - astral projection, command undead (DC 18), desecrate, detect good, detect law, enervation (+31 ranged touch), greater dispel magic, greater teleport, telekinesis (DC 19), unhallow, unholy blight (DC 18)
3/day - quickened enervation (+31 ranged touch), finger of death (DC 23), symbol of death (DC 24)
1/day - wail of the banshee (DC 25)
Special Qualities: tanarri traits; Immunities: ability drain, critical hits, death effects, electricity, energy drain, mind-affecting spells and abilities, negative energy, paralysis, poison, sneak attacks; Resist: acid 10, cold 10, fire 10; SR 35
Feats: Dark Speech, Greater Spell Focus (necromancy), Hover, Improved Critical (heavy mace), Improved Initiative, Multiattack, Quicken Spell-Like Ability (enervation), Spell Focus (necromancy), Weapon Focus (heavy mace),
Skills: Bluff +33, Climb +41, Concentration +42, Craft (alchemy) +37, Diplomacy +8, Escape Artist +35, Forgery +37, Intimidate +35, Knowledge (arcana) +37, Knowledge (religion) +37, Knowledge (the planes) +37, Listen +34, Search +37, Sense Motive +34, Spellcraft +39, Spot +34, and Use Magic Device +33
Advancement: -
Climate/Terrain: The Abyss (Thanatos)
Organization: Orcus plus 1d6 vampires or liches
Treasure/Possessions: Wand of Orcus, quadruple treasure

Source: Book of Vile Darkness
Fiendish Codex I

Poison (Ex): Sting - Injury, Fortitude DC 36, 1d6 Str/2d6 Str. The save DC is Constitution-based.

Summon Tanar'ri (Sp): Once per day, Orcus can automatically summon 1d6 vrocks, 1d4 glabrezu, or 1 marilith. This ability functions as a 9th-level spell (CL 20th).

Summon Undead (Sp): Once per day, Orcus can automatically summon 4d10 wights, 1d8 spectres, or 1d3 mohrgs. This ability functions as a 9th-level spell (CL 20th).

Wand of Orcus: The weapon that Orcus wields functions as a +6 unholy anarchic heavy mace. If the wand touches any non-outsider, or any outsider with less than 15 HD, the target must succeed on a DC 25 Fortitude save or be instantly slain. This is a necromantic death effect. The wand also confers a +5 deflection bonus to the Armor Class of its wielder.

Updated to 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).