Ichthyosaurus

From the deck of your boat, you see a fin, a really big fin. A prehistoric shark-looking creatures snaps at the boat. You suddenly realise your going to need a bigger boat.

Originally posted on Mystara by Jamie Baty

The ichthyosaurus is a sea-dwelling dinosaur shaped much like a shark but with flippers near the front of its body. It has a long, tooth-filled, beak-like mouth and enormous, plate-sized eyes. It is roughly 30ft in length. It eats fish, squid, and swimmers.

Icthyosaurus
Huge animal
Hit Dice	10d8+60 (105 hp)
Initiative	+5 (+1 Dexterity, +4 Improved Initiative)
Speed	Swim 80 ft. (16 squares)
Armour Class	14 (-2 size, +1 Dexterity, +5 natural), touch 9, flat-footed 13
Base Attack/Grapple	+7/+25
Attack	Bite +15 melee (2d6 +10)
Full Attack	Bite +15 melee (2d6 +10)
Space/Reach	15 ft. /10 ft.
Special Attacks	Improved grab, swallow whole
Special Qualities	Low-Light Vision, Scent
Saves	Fort +14, Ref +8, Will +2
Abilities	Strength 31, Dexterity 13, Constitution 23, Intelligence 2, Wisdom 8, Charisma 6
Skills	Hide+2, Listen +4, Move Silently +3, Spot +4, Survival+ 0, Swim +21
Feats	Alertness, Die Hard, Improved Initiative, Track
Environment	Any aquatic
Organisation	Solitary, Pair, or Pack (2-5)
Challenge Rating	9
Treasure	None
Alignment	Always neutral
Advancement	11-20 HD (Huge); 21-30 HD (Gargantuan)
Level Adjustment	–

Combat

The ichthyosaurus will relentlessly Track it prey, and rarely will flee a battle. If it tastes blood, it will pursue the wounded creature and attack it as soon as possible.

Improved Grab (Ex): If an ichthyosaurus hits with its bite attack, it deals normal damage and attempts to start a grapple as a free action without provoking an attack of opportunity. If the grapple succeeds, the ichthyosaurus may hold the victim and inflict bite damage automatically. After the hold is established, it may attempt to swallow the creature in any following round.

Swallow Whole (Ex): An ichthyosaurus 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 ichthyosaurus’s gizzard. A swallowed creature can cut its way out by using a light slashing or piercing weapon to deal 20 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 Huge ichthyosaurus’s gizzard can hold 2 Medium, 8 Small, 32 Tiny, or 128 Diminutive or smaller opponents.

Scent (Ex): This special quality allows a ichthyosaurus to detect approaching enemies, sniff out hidden foes, and Track by sense of smell.

Skills: Ichthyosaurs have a +8 racial bonus to Swim and Hide checks.