Caller from the Deeps (CR 9)

Huge Elemental (Water)
Alignment: Always neutral evil
Initiative: -1 (Dex); Senses: darkvision 60 ft., Listen +13, and Spot +13

AC: 22 (-1 Dex, -2 size, +15 natural), touch 7, flat-footed 22
Hit Dice: 9d8+90 (130 hp); DR: 5/-
Fort +16, Ref +2, Will +4
Speed: Swim 50 ft.
Space: 15 ft./15 ft.
Base Attack +6; Grapple +22
Attack: Tentacle +13 melee
Full Attack: 2 tentacles +13 melee
Damage: Tentacle 2d6+8
Special Attacks/Actions: Constrict 2d6+8, enervating grip, improved grab
Abilities: Str 26, Dex 9, Con 30, Int 15, Wis 12, Cha 14
Special Qualities: elemental traits, siren's call, summon watery ally
Feats: Combat Reflexes; Improved Natural Attack (tentacles); Swim-By Attack; Weapon Focus (tentacles)
Skills: Concentration +22, Listen +13, Spot +13, and Swim +28
Advancement: 10-18 HD (Huge); 19-27 HD (Gargantuan)
Climate/Terrain: Any aquatic
Organization: Solitary
Treasure/Possessions: None

Source: Stormwrack

Constrict (Ex): A caller from the deeps deals automatic tentacle damage with a successful grapple check.

Enervating Grip (Su): While dealing damage in a grapple, a caller from the deeps also drains the vitality of its target. Those who take grappling damage from a taller from the deeps must make a DC 24 Fortitude save or take 1 point of Constitution damage. This save DC is Constitution-based.

Improved Grab (Ex): To use this ability, a caller from the deeps must hit with a tentacle attack. It can then attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple, it establishes a hold and can both constrict and use its enervating grip ability.

Elemental Traits: A caller from the deeps has immunity to poison, magic sleep effects, paralysis, and stunning. It is not subject to critical hits or flanking. It cannot be raised, reincarnated, or resurrected (though a limited wish, wish, miracle, or true resurrection spell can restore it to life).

Siren's Call (Sp): Three times per day, a caller from the deeps can use a siren's call effect (DC 18).

Summon Watery Ally (Sp): Once per hour, a caller from the deeps can summon a Medium water elemental or a Large fiendish shark. This creature remains for 10 minutes or until slain. This is the equivalent of a 4th-level spell.

Skills: A caller from the deeps has a +8 racial bonus on its Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on any swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

A caller from the deeps maintains a very simple technique for hunting. It begins by calling its prey to itself, using siren's call. It then grapples those who enter the water, drowning them. Should any manage to put up enough of a fight to endanger its serenity, it summons a creature to defend itself and distract any adversaries. Only if its opponents fight their way past this summoned minion or manage to directly engage the caller itself will this creature focus its full attention and might on them.

Water Subtype

This subtype usually is used for elementals and outsiders with a connection to the Elemental Plane of Water. Creatures with the water subtype always have swim speeds and can move in water without making Swim checks. A water creature can breathe underwater and usually can breathe air as well.