Octopus, Giant (CR 8)

Large Animal (Aquatic)
Alignment: Always neutral
Initiative: +2 (Dex); Senses: low-light vision, Listen +4, and Spot +6

AC: 18 (-1 size, +2 Dex, +7 natural), touch 11, flat-footed 16
Hit Dice: 8d8+11 (47 hp)
Fort +7, Ref +8, Will +3
Speed: 20 ft., swim 30 ft.
Space: 10 ft./10 ft. (20 ft. with tentacle)
Base Attack +6; Grapple +15
Attack: Tentacle +10 melee
Full Attack: 8 tentacles +10 melee and bite +5 melee
Damage: Tentacle 1d4+5, bite 1d8+2
Special Attacks/Actions: Improved grab, constrict
Abilities: Str 20, Dex 15, Con 13, Int 2, Wis 12, Cha 3
Special Qualities: Ink cloud, jet
Feats: Alertness; Skill Focus (Hide); Toughness
Skills: Escape Artists +12, Hide +12, Listen +4, Spot +6, and Swim +13
Advancement: 9-12 HD (Large); 13-24 HD (Huge)
Climate/Terrain: Warm aquatic
Organization: Solitary
Treasure/Possessions: None

Source: Monster Manual

Improved Grab (Ex): To use this ability, the giant octopus, 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 octopus deals 2d8+6 points of damage with a successful grapple check against Medium-size or smaller creatures.

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

Jet (Ex): A giant octopus can jet backward once a round as a double move action, at a speed of 200 feet.

Skills: A giant octopus can change colors, giving it a +4 racial bonus to Hide checks.

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.