The Gristlygnash by SPipes

Edit: Now, Finally, with stats!

------

Gristlygnash
Large Undead (Aquatic)
Hit Dice: 6d12+0 (36 hp)  
Initiative: +0
Speed: 40 ft. (8 squares), Swim 60 ft. (12 squares)
Armor Class: 17 (–1 size, +0 Dex, +8 natural), touch 9, flat-footed 17
Base Attack/Grapple: +3/+15  
Attack: Bite +11 melee (1d8+9)  
Full Attack: 2 bites +10 melee (1d8+9), +5 slam (1d8+4), and bite +5 melee (2d6+4)  
Space/Reach: 10 ft./5 ft.  
Special Attacks: Improved grab, rend
Special Qualities: Blindsense, keen scent, low-light vision, scent
Saves: Fort +3, Ref +3, Will +3  
Abilities: Str 29, Dex 11, Con —, Int —, Wis 10, Cha 1  
Skills: Listen +4, Spot +7, Swim +12  
Feats: Endurance, Run, Track  
Environment: Cold forests or cold aquatic
Organization: Solitary or pair  
Challenge Rating: 6  
Treasure:
None

Alignment:
Always neutral evil
Advancement: 7–10 HD (Large)  
Level Adjustment: —

Legend says the gristlygnash was spawned from the nightmares of a sorcerer, or in a drunken bet between necromancers. Regardless, it's unliving proof that some things are so much worse than the sum of their parts.

These horrific creatures are crafted from the remains of three massive predators. They are often found as the guardians of a necromancer's sanctum, especially if one that includes a moat or other water features. These rotting monstrosities weigh over 1,800 pounds and stand nearly 9 feet tall when they rears up on their hind legs. Knowing only a searing need for predation, they are savage and relentless in pursuit of living prey. They are equally at home in water and on land.
A gristlygnash attacks mainly by tearing at opponents with its shark mouths.
Improved Grab (Ex): To use this ability, a gristlygnash must hit with a claw attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity.
Blindsense (Ex): A gristlygnash can locate creatures underwater within a 30-foot radius. This ability works only when the gristlygnash is underwater.
Keen Scent (Ex): A gristlygnash can notice creatures by scent in a 180-foot radius and detect blood in the water at ranges of up to a mile.  
Rend (Ex): If a gristlygnash hits with both claw attacks, it latches onto the opponent’s body and tears the flesh. This attack automatically deals an additional 2d6+9 points of damage.
Skills: A gristlygnash 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.