Blood Mother (CR 18)

Large Outsider
Alignment: Always chaotic evil
Initiative: +10 (Dex); Senses: Listen +30 and Spot +30
Languages: Blood Elemental

AC: 28 (+10 Dex, +9 natural, -1 size), touch 19, flat-footed 18
Hit Dice: 24d8+72 (180 hp); DR: 10/magic
Fort +17, Ref +24, Will +17
Speed: 20 ft., swim 90 ft. (30 ft. in mortal form)
Space: 10 ft./10 ft.
Base Attack +24; Grapple +24
Attack: Slam +27 melee
Full Attack: Slam +27 melee
Damage: 2d6+7 slam
Special Attacks/Actions: Bloodbath, cause insanity, frightful presence, spells
Abilities: Str 21, Dex 31, Con 16, Int 20, Wis 17, Cha 16
Special Qualities: Assume mortal form, incomprehensible, outsider traits, immunities (critical hits, mind-affecting effects, stunning), SR 20
Feats: Cleave; Combat Casting; Heighten Spell; Maximize Spell; Power Attack; Quicken Spell; Improved Sunder
Skills: Bluff +30, Concentration +30, Diplomacy +9, Intimidate +34, Knowledge (arcana) +32, Knowledge (the planes) +32, Listen +30, Move Silently +37, Search +32, Sense Motive +18, Spellcraft +32, Spot +30, and Swim +40
Advancement: 25-30 HD (Huge)
Climate/Terrain: Any
Organization: Solitary
Treasure/Possessions: None

Source: Web

Bloodbath (Ex): With a successful grapple check (grapple bonus +33, including a +5 racial bonus on grapple checks), a blood mother may engulf a creature of up to its own size category. Creatures so engulfed face drowning (see Drowning). The blood mother may eject the engulfed creature at any time. A victim that is still alive when it emerges from the blood mother's body (whether by escaping the monster's hold or by being ejected) takes 1d6 points of Wisdom damage because of the strain on its sanity that the sensation of drowning in blood produced. Furthermore, the victim creature must make a successful Fortitude save (DC 25) on emerging or be nauseated for 2d6 rounds.

Cause Insanity (Su): Six times per day, a blood mother in its normal form may attempt to drive a living target insane. This ability functions like the insanity spell (caster level 18th; save DC 25).

Frightful Presence (Su): When a blood mother assumes its normal form, it inspires terror in all creatures within 30 feet that have fewer Hit Dice or levels than it has. Each potentially affected opponent must succeed at a Will save (DC 25) or become panicked for 4d6 rounds if it has 4 or fewer Hit Dice or shaken for 4d6 rounds if it has 5 or more Hit Dice. A successful save leaves that opponent immune to that blood mother's frightful presence for 24 hours.

Spells: A blood mother can cast spells as a 13th-level cleric. It has access to spells from the Evil and Death domains, though it does not receive extra domain spell slots or granted powers. Spells per day: 6/ 6/6/5/4/3/2/1; save DC 13 + spell level.

Assume Mortal Form (Sp): As a standard action, the blood mother may transform itself into a middle-aged human female, as if using the spell polymorph self (caster level 18th). While in mortal form, the blood mother may not use its bloodbath or cause insanity special abilities, but it may converse normally with mortal creatures. A blood mother in mortal form has perpetually ruddy skin, as though constantly blushing.

When a blood mother is in human form, the following changes apply to its statistics: Medium-size outsider; Spd 30 ft., swim 90 ft.; AC 29, touch 20, flat-footed 19; Atk +28 melee (2d6+7, slam); Face/ Reach 5 ft. by 5 ft./5 ft.

Immunities (Ex): The blood mother's alien psychology and physiology make it immune to critical hits, mind-affecting effects, stunning.

Incomprehensible (Ex): Because of the blood mother's alien mentality, the gurgling language it speaks in its normal form cannot be understood by any creature except blood elementals and other blood mothers. No mundane or magical effect that usually allows verbal communication (including a tongues spell or a monk's tongue of the sun and moon ability) allows any other creature to understand it. Blood mothers can, however, learn the languages of other species to the limits of their Intelligence. They can understand such languages while in their natural form, but they can speak them only in mortal form. Because they are capable of understanding other languages, blood mothers are not immune to language-dependent effects.

Summon Blood Elemental (Sp): Three times per day, a blood mother may summon 1d6 blood elementals to assist it. She may communicate with them even while in mortal form.