XP 4,915,200
CE Huge outsider (chaotic, demon, evil, extraplanar, water)
Init +11; Senses darkvision 60 ft., detect good, detect law, true seeing; Perception +55
Aura frightful presence (120 ft., DC 36), unholy aura (DC 28)

DEFENSE

AC 46, touch 31, flat-footed 39 (+4 deflection, +7 Dex, +15 natural, +12 profane, –2 size)
hp 676 (33d10+495); regeneration 30 (deific or Mythic)
Fort +37, Ref +24, Will +33
Defensive Abilities Abyssal resurrection, freedom of movement; DR 20/cold iron, epic, and good; Immune ability damage, ability drain, charm effects, compulsion effects, cold, death effects, electricity, energy drain, petrification, and poison; Resist acid 30, fire 30; SR 39

OFFENSE

Speed 40 ft., swim 120 ft.
Melee bite +48 (6d6+17/19–20 plus grab), 4 tentacles +43 (2d6+8/19–20 plus grab)
Space 15 ft.; Reach 15 ft. (30 ft. with tentacle)
Special Attacks breath weapon, command aquatic creature, constrict (2d6+25), fast swallow, poison, swallow whole (transformation, AC 17, 67 hp)
Spell-Like Abilities (CL 28th; concentration +38)

Constant—detect good, detect law, freedom of movement, speak with animals (aquatic animals only), true seeing, unholy aura (DC 28)
At will—astral projection, blasphemy* (DC 27), control water, control weather*, desecrate*, greater dispel magic, greater teleport, shapechange, telekinesis* (DC 25), unhallow, unholy blight* (DC 24)
3/day—quickened greater dispel magic, insanity (DC 27), summon demons, symbol of insanity (DC 28), vortex (DC 27)
1/day—storm of vengeance* (DC 29), time stop*, tsunami*, (DC 29)

*Dagon can use the Mythic version of this ability in his realm.

STATISTICS

Str 44, Dex 25, Con 40, Int 29, Wis 32, Cha 31
Base Atk +33; CMB +52 (+56 bull rush, +54 disarm, +56 grapple, +54 trip); CMD 87 (89 vs. bull rush, 89 vs. disarm, can't be tripped)
Feats Awesome Blow, Bleeding Critical, Combat Expertise, Combat Reflexes, Craft Wondrous Item, Critical Focus, Greater Bull Rush, Improved Bull Rush, Improved Critical (bite), Improved Critical (tentacle), Improved Initiative, Improved Trip, Improved Vital Strike, Lightning Reflexes, Power Attack, Quicken Spell-Like Ability (greater dispel magic), Vital Strike
Skills Acrobatics +40 (+44 when jumping), Bluff +46, Intimidate +46, Knowledge (arcana) +45, Knowledge (geography) +42, Knowledge (history) +42, Knowledge (nature) +45, Knowledge (planes) +45, Knowledge (religion) +42, Perception +55, Sense Motive +47, Spellcraft +45, Stealth +35, Swim +61, Use Magic Device +43; Racial Modifiers +8 Perception
Languages Abyssal, Aquan, Celestial, Common, Draconic; speak with animals (aquatic animals only), telepathy 300 ft.
SQ compression, demon lord traits

SPECIAL ABILITIES

Breath Weapon (Su)

Once every 1d4 rounds as a standard action, Dagon can exhale a 60-foot cone of inky blackness. Underwater, this cone manifests as black ink, while above water it manifests as a thick cloud. Creatures in the area have their vision obscured as if they were in complete darkness. Darkvision does not allow someone to see through the ink or smoke, but true seeing does. The ink or smoke persists for 1d4 rounds, but dissipates in 1 round in areas with aquatic currents or winds. Any creature in the breath weapon's area is exposed to the breath weapon's poison (see below) and must succeed at a DC 41 Will save or gain 2 negative levels as its memories and knowledge leach away (this is a mind-affecting effect). Any creature that enters the ink or cloud, or ends its turn inside it, must succeed at another Will save (at a +4 bonus) to avoid further level loss and poisoning. The save DC is Constitution-based.

Command Aquatic Creature (Su)

Dagon can command aquatic creatures to do his bidding as a move action, either via using his ability to speak with animals or via telepathy. This affects all aberrations, animals, magical beasts, oozes, and vermin within 300 feet that have the aquatic subtype (Will DC 36 negates). This functions like mass suggestion, but can affect mindless creatures. Dagon can suggest obviously harmful or suicidal acts (though non-mindless creatures gain a +10 bonus on their saving throws against these suggestions). The commanded course of activity can have a duration of up to 1 hour. If Dagon issues a new command to a creature, the previous command is discarded. Once a creature succeeds at its save against this effect, it is immune to further commands from Dagon for 24 hours. The save DC is Charisma-based.

Poison (Ex)

Breath weapon—contact; save Fort DC 41; frequency 1/round for 6 rounds; effect 1d6 Con drain and confused for 1 round; cure 3 consecutive saves.

Transformation (Su)

A creature swallowed by Dagon is assaulted by demonic enzymes, rasping talons, sucking tendrils, and vile gases. At the start of the swallowed creature's turn, it must succeed at a DC 41 Fortitude save or be nauseated, and must succeed at a DC 36 Will save or take 1d6 points of Dexterity and Charisma drain. Once the creature's Dexterity and Charisma are drained to 0, the creature transforms into a horrifically deformed version of itself that Dagon can then disgorge into any adjacent square as a swift action. The transformed creature gains the half-fiend template, its Dexterity and Charisma return to their normal values, and it is under Dagon's control (as dominate monster, caster level 28th). The transformation can be reversed by casting break enchantment and atonement on the victim during the first 24 hours (after that, it can be reversed only via miracle or wish). The Fortitude save DC is Constitution-based, and the Will save DC is Charisma-based.