Kraken (CR 12)

Gargantuan Magical Beast (Aquatic)
Alignment: Always neutral evil
Initiative: +4 (Improved Initiative); Senses: darkvision 60 ft., low-light vision, Listen +30, and Spot +30

AC: 20 (-4 size, +14 natural), touch 6, flat-footed 20
Hit Dice: 20d10+180 (290 hp)
Fort +21, Ref +12, Will +13
Speed: Swim 20 ft.
Space: 20 ft./15 ft. (60 ft. with tentacle, 30 ft. with arm)
Base Attack +20; Grapple +44
Attack: Tentacle +28 melee
Full Attack: 2 tentacle +28 melee and 6 arms +23 melee and bite +23 melee
Damage: Tentacle 2d8+12/19-20, arm 1d6+6, bite 4d6+6
Special Attacks/Actions: Improved grab, constrict 2d8+12 or 1d6+6
Abilities: Str 34, Dex 10, Con 29, Int 21, Wis 20, Cha 10
Special Qualities: Jet, ink cloud, low-light vision, spell-like abilities
Feats: Alertness; Blind-fight; Combat Expertise; Improved Critical (tentacle); Improved Initiative; Improved Trip; Iron Will
Skills: Concentration +21, Diplomacy +7, Hide +0, Intimidate +16, Knowledge (geography) +17, Knowledge (nature) +16, Listen +30, Search +28, Spot +30, Survival +5 (+7 following tracks), Swim +20, and Use Magic Device +16
Advancement: 21-32 HD (Gargantuan); 33-60 HD (Colossal)
Climate/Terrain: Temperate aquatic
Organization: Solitary
Treasure/Possessions: Triple standard

Source: Monster Manual

Improved Grab (Ex): To use this ability, the kraken must hit an opponent of up to Huge size with an arm or tentacle attack. If it gets a hold, it can constrict.

Constrict (Ex): A kraken deals automatic arm or tentacle damage with a successful grapple check against Huge or smaller creatures.

Jet (Ex): A kraken can jet backward once per round as a double move action, at a speed of 280 feet.

Ink Cloud (Ex): A kraken can emit a cloud of jet-black ink 80 feet high by 80 feet wide by 120 feet long once per minute as a free action. The cloud provides total concealment, which the kraken normally uses to escape a losing fight. Creatures within the cloud suffer the effects of total darkness.

Spell-Like Abilities: 1/day - control weather, control winds, dominate animal, and resist elements. These abilities are as the spells cast by a 9th-level druid (save DC 15 + spell level).

Krakens strike their opponents with their barbed tentacles, then grab and crush with their arms or drag victims into their huge jaws.

Aquatic Subtype

Creatures with the aquatic subtype always have swim speeds and thus can move in water without making Swim checks. An aquatic creature can breathe underwater. It cannot also breathe air unless it has the amphibious special quality.