Squid, Giant (CR 9)

Huge Animal (Aquatic)
Alignment: Always neutral
Initiative: +3 (Dex); Senses: low-light vision, Listen +10, and Spot +11

AC: 17 (-2 size, +3 Dex, +6 natural), touch 11, flat-footed 14
Hit Dice: 12d8+12 (66 hp)
Fort +9, Ref +11, Will +5
Speed: Swim 80 ft.
Space: 15 ft./15 ft.
Base Attack +9; Grapple +29
Attack: Tentacle +15 melee
Full Attack: 10 tentacle +15 melee and bite +10 melee
Damage: Tentacle 1d6+8, bite 2d8+4
Special Attacks/Actions: Improved grab, constrict 1d6+8
Abilities: Str 26, Dex 17, Con 13, Int 1, Wis 12, Cha 2
Special Qualities: Ink cloud, jet
Feats: Alertness; Diehard; Endurance; Toughness (2)
Skills: Listen +10, Spot +11, and Swim +16
Advancement: 13-18 HD (Huge); 19-36 HD (Gargantuan)
Climate/Terrain: Temperate aquatic
Organization: Solitary
Treasure/Possessions: None

Source: Monster Manual

Improved Grab (Ex): To use this ability the giant squid must hit a Medium-size or smaller opponent with a tentacle rake attack. If it gets a hold, it can constrict.

Constrict (Ex): A giant squid deals automatic tentacle damage with a successful grapple check against Medium-size or smaller creatures.

Ink Cloud (Ex): A giant squid can emit a cloud of jet-black ink 20 feet high by 20 feet wide by 40 feet long once a minute as a free action. The cloud provides total concealment, which the squid normally uses to escape a losing fight. Creatures within the cloud suffer the effects of total darkness.

Jet (Ex): A giant squid can jet backward once a round as a double move action, at a speed of 320 feet.

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.