Legendary Shark (CR 10)

Huge Animal (Aquatic)
Alignment: Always neutral
Initiative: +4 (Dex); Senses: keen scent, low-light vision, Listen +19, and Spot +18

AC: 22 (-2 size, +4 Dex, +10 natural), touch 12, flat-footed 18
Hit Dice: 30d8+237 (372 hp)
Fort +24, Ref +21, Will +19
Speed: Swim 100 ft.
Space: 15 ft./10 ft.
Base Attack +22; Grapple +39
Attack: Bite +30 melee
Full Attack: Bite +30 melee
Damage: Bite 2d8+13
Special Attacks/Actions: Improved grab, swallow whole
Abilities: Str 28, Dex 19, Con 24, Int 1, Wis 14, Cha 7
Special Qualities:
Feats: Improved Critical (Bite); Toughness x9; Weapon Focus (bite)
Skills: Listen +19, Spot +18, and Swim +17
Advancement: 31-60 HD (Huge)
Climate/Terrain: Any aquatic
Organization: Solitary, pair, or school (3-5)
Treasure/Possessions: None

Source: Monster Manual II

Improved Grab (Ex): If a legendary shark hits a Large or smaller opponent with a bite attack, it deals normal damage and attempts to start a grapple as a free action without provoking an attack of opportunity (grapple bonus +39). If it gets a hold, it can try to swallow in the next round. Alternatively, the legendary shark has the option to conduct the grapple normally, or simply use its mouth to hold the opponent (-20 penalty on grapple check, but the legendary shark is not considered grappled). In either case, each successful grapple check it makes during successive rounds automatically deals bite damage.

Swallow Whole (Ex): A legendary shark can swallow a Large or smaller creature by making a successful grapple check (grapple bonus +39), provided it already has that opponent in its maw (see Improved Grab, above). Once inside the legendary shark, the opponent takes 2d8+13 points of bludgeoning damage plus 1d8+4 points of acid damage per round from the shark's stomach. A successful grapple check allows the swallowed creature to climb out of the stomach and return to the legendary shark's mouth, where another successful grapple check is needed to get free. Alternatively, a swallowed creature can try to cut its way out with either claws or a light piercing or slashing weapon. Dealing at least 50 points of damage to the stomach (AC 18) in this way creates an opening large enough to permit escape. Once a single swallowed creature exits, muscular action closes the hole; thus, another swallowed opponent must cut its own way out. A legendary shark's stomach can hold up to 2 Large, 8 Medium-size, 32 Small, or 128 Tiny or smaller opponents.

Keen Scent (Ex): A legendary shark notices creatures by scent in a 180-foot radius and detects blood in the water at a range of up to 1 mile.

Saving Throws: A legendary animal has all good saves.

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.