Avatar of Ythog-Nthlei
Huge Outsider (Evil, Extraplanar, Native)
Hit Dice: 21d8+210 (304 hp)
Initiative: +5
Speed: 30 ft. (6 squares)
Armor Class: 32 (-2 size, +1 Dex, +6 deflection, +5 insight, +12 natural), touch 20, flat-footed 31
Base Attack/Grapple: +21/+39
Attack: Blacklight mace +34 melee (3d6+15/19-20) and eyebeam +20 ranged touch (1d4+1 Str); or bite +29 melee (2d6+10 plus slave venom) and eyebeam +15 ranged touch (1d3 Str); or 4 eyebeams +20 ranged touch (1d3 Str)
Full Attack: Blacklight mace +34/+29/+24/+19 melee (3d6+15/19-20) and bite +24 melee (2d6+5 plus slave venom) and eyebeam +15 ranged touch (1d3 Str); or 4 eyebeams +20 ranged touch (1d3 Str)
Space/Reach: 15 ft./15 ft.
Special Attacks: Eyebeams, spell-like abilities, slave venom
Special Qualities: Beyond reality, immunities, reflect spell, squeeze
Saves: Fort +22, Ref +13, Will +17
Abilities: Bluff +30, Climb +22, Concentration +34, Diplomacy +34, Intimidate +32, Knowledge (arcana) +16, Knowledge (dungeoneering) +16, Knowledge (religion) +16, Knowledge (the planes) +16, Listen +29, Sense Motive +29, Spot +29, Spellcraft +30 (+32 deciphering scrolls), Survival +5 (+7 underground and on other planes), Swim +22, Use Magic Device +30 (+32 with scrolls)
Feats: Awesome Blow, Cleave, Dire Charge, Improved Critical (mace), Improved Bull Rush, Improved Initiative, Power Attack, Quicken Spell-Like Ability (greater dispel magic)
Environment: Any
Organization: Solitary or court (1 plus 1-2 sentinel eidolons and 2-5 priests of Ythog Nthlei)
Challenge Rating: 18
Treasure: Double standard
Alignment: Neutral evil
Advancement: —
Level Adjustment: —
An immense giant garbed in a yellow robe, roughly three times taller than a human. Its bulbous face is a nightmarish combination of a giant snail and a malevolent male human, topped with a crown of four eyestalks. In one hand it hefts a massive black mace.
An Aspect of Nthog-Ythlei is 18 feet tall and weighs 15,000 pounds.
COMBAT
Beyond Reality (Ex): Ythog-Nthlei is an uncanny being who belongs to no known plane of existence, but is comfortable in all of them. He possesses both the Extraplanar and Native subtypes on every plane, using whichever subtype is most advantageous on a case-by-case basis. For example, he could simultaneously answer the call of a gate spell as an extraplanar creature, then ignore that spell's control as a native creature.
Ythog-Nthlei can attack incorporeal and out-of-phase targets without penalty and ignores the effects of blink or displacement powers. He sees all adjacent dimensions clearly, including the Astral Plane, Ethereal Plane and the interiors of extradimensional spaces such as a rope trick, maze or portable hole.
Blacklight Mace: This gargantuan weapon is a +3 heavy mace when wielded by others creatures, but functions as a +5 heavy mace for an Aspect of Ythog-Nthlei. Three times a day, as a swift action, the Aspect can command his mace to radiate deeper darkness (as the spell) in a 30 foot radius (20% miss chance, impenetrable to normal vision and darkvision). Once activated, the blacklight mace continues to radiate deeper darkness until The Dark King loses contact with it or commands it to stop (another swift action). Ythog-Nthlei can always see through this darkness normally, even if he is outside the area of darkness. Deeper darkness counters or dispels any light spell of equal or lower level. A daylight spell will temporarily counter this deeper darkness, but the darkness returns as soon as the daylight ends.
Furthermore, the Aspect of Ythog-Nthlei (but no other wielder) can command the blacklight mace to summon 4d6 walking dead with the Extraplanar subtype. This is equivalent to a summon monster VII.
The blacklight mace crumbles to black powder and evaporates into nothingness if the Aspect of Ythog-Nthlei is killed or if it is separated from the Aspect for more than 24 hours. The Aspect can recreate a destroyed blacklight mace as a full-round action.
Overwhelming evocation/necromancy [evil]; CL 20th.
Eyebeams (Su): Ythog-Nthlei's eyebeams are 200 foot range ray attacks (no range increments) that do 1d3 Strength damage if they hits. Ythog-Nthlei can make a single eyebeam attack as a swift action once per round or up to 4 eyebeam attacks as a standard action, but he cannot produce more than four eyebeams in a round (one from each eye).
Immunities: Ythog-Nthlei is immune to disease, poison, energy drain, cold damage and mind-affecting effects. His Beyond Reality ability give him special immunity to effects that banish extraplanar creatures and certain extradimensional effects, such as the miss chance of a blink spell.
Reflect Spell (Su): Any spell that specifically targets Ythog-Nthlei is reflected back onto its caster as per the spell turning spell.
Slave Venom (Su): Any living creature hit by Ythog-Nthlei's bite attack must succeed at a DC 26 Fortitude save or be dominated by the Dark King for 1d10 rounds. The domination functions like the dominate monster spell. This supernatural venom can affect creatures immune to mind-affecting attacks or poison, but such immunity grants the victim a +4 bonus on their save (+8 if they're immune to both poison and mind-affecting effects, such as a Plant or Ooze). Creatures with saving throw bonuses against poison or compulsion effects (such as a dwarf's +2 against poison or an elf's +2 against enchantments) apply these bonuses when saving against Slave Venom. Slave Venom has no effect on nonliving creatures such as Constructs and Undead. Its save DC is Charisma-based.
Spell-Like Abilities (Sp): At will—arcane sight, detect scrying, dispel magic, false vision, plane shift (DC 23), prying eyes, greater teleport, true seeing, unhallow, 3/day—quickened dispel magic, 1/day—legend lore. Caster level 20th. The save DCs are Charisma-based.
Squeeze (Ex): Ythog-Nthlei's gelatinous body allows him to freely move and fight through any opening large enough to pass a Large creature. He can squeeze through openings a Medium creature can fit through with a DC 30 Escape Artist check.
Originally appeared in Dragon #46.
Skill Breakdown
Bluff 24+Cha6
Climb 12+Str10
Concentration 24+Con10
Diplomacy 24+Cha6+4synergy
Intimidate 24+Cha6+2synergy
Knowledge (arcana) 12+Int4
Knowledge (dungeoneering) 12+Int4
Knowledge (religion) 12+Int4
Knowledge (the planes) 12+Int4
Listen 24+Wis5
Sense Motive 24+Wis5
Spot 24+Wis5
Spellcraft 24+Int4+2synergy (+2 deciphering scrolls)
Survival 0+Wis5 (+2 underground and on other planes)
Swim 12+Str10
Use Magic Device 24+Cha6 (+2 with scrolls)
You can enter that one in the CC, too. 
