Dinosaur, Kronosaurus
Gargantuan Animal

Hit Dice: 16d8+105 (177 hp)
Initiative: +1
Speed: 10 ft. (2 squares), swim 40 ft.
AC: 18 (-4 size, +1 Dex, +11 natural), touch 7, flat-footed 17
Attacks: Bite +8 melee and slam +3 melee
Damage: Bite (3d8+12) and slam (1d8+18)
Face/Reach: 40 ft./20 ft.
Special Attacks: Improved Grab, Swallow Whole
Special Qualities: Low-light vision, Amphibious
Saves: Fort +11, Ref +11 Will +6
Abilities: Str 35, Dex 12, Con 23, Int 1, Wis 12, Cha 2
Skills: Hide -6*, Listen +8, Spot +8, Swim +12
Feats Alertness, Endurance, Improved Natural Attack (Bite), Toughness (3)
Climate/Terrain: Warm ocean
Organization: Solitary or pair
Challenge Rating: 12
Treasure: None
Alignment: Always neutral
Advancement: -
Level Adjustment: -
This massive creature measures over 42 feet long, and appears to be a giant crocodile with fins.
COMBAT
Improved Grab (Ex): To use this ability, a kronosaurus must hit an opponent of up to one size smaller with its bite attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and can try to swallow the foe the following round.
Swallow Whole (Ex): A kronosaurus can try to swallow a grabbed opponent of up to two sizes smaller by making a successful grapple check. The swallowed creature takes 2d8+8 points of bludgeoning damage and 8 points of acid damage per round from the kronosaurus’s gizzard. A swallowed creature can cut its way out by using a light slashing or piercing weapon to deal 35 points of damage to the gizzard (AC 12). Once the creature exits, muscular action closes the hole; another swallowed opponent must cut its own way out.
A Gargantuan kronosaurus’s gizzard can hold 2 Large, 8 Medium, 32 Small, or 128 Tiny or smaller opponents.
Skills: A kronosaurus has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line. *A kronosaurus gains a +4 racial bonus on Hide checks when in the water. Further, a kronosaurus can lie in the water with only its eyes and nostrils showing, gaining a +10 cover bonus on Hide checks.