Charnel Hound (CR 13)

Huge Undead
Alignment: Always chaotic evil
Initiative: +2 (Dex); Senses: darkvision 60 ft.

AC: 26 (-2 size, +2 Dex, +16 natural), touch 10, flat-footed 24
Hit Dice: 21d12+84 (220 hp); DR: 10/silver and magic
Fort +7, Ref +9, Will +12
Speed: 40 ft.
Space: 15 ft./10 ft.
Base Attack +10; Grapple +32
Attack: Bite +17 melee
Full Attack: Bite +17 melee and 2 claws +12 melee (Includes adjustments for Power Attack feat.)
Damage: Bite 2d8+19, Claw 2d6+12
Special Attacks/Actions: Body integration, rend 4d6+21
Abilities: Str 38, Dex 14, Con -, Int -, Wis 11, Cha 18
Special Qualities: Aversion to daylight, frightful presence, SR 23, undead traits, unholy toughness
Feats: Power Attack
Skills: -
Advancement: 22-31 HD (Huge); 32-63 HD (Gargantuan)
Climate/Terrain: Cold plains
Organization: Solitary, pair, or gang (3-4)
Treasure: Standard

Source: Monster Manual III

The hound-shaped creature stands at least 20 feet at the shoulder. Closer scrutiny reveals that while the creature has the outward shape of a hound, its form is composed of the bodies of hundreds of rotting humanoid corpses.

Charnel hounds are a stunning achievement of some crazed necromancer or god of death. Their very presence is a proclamation of necromantic power. The way in which the bodies making up a charnel hound's form sometimes scream, mutter, and jerk serves to horrify and frighten onlookers.

Charnel hounds, once created, are self-sufficient engines of undead destruction found at night roaming plains where battles have been fought, or loose in underground areas large enough to accommodate their bulk. During the day, they dig themselves great burrows to escape the sun. When clerics or necromancers are powerful enough to command a charnel hound, it is often used as a guardian.

A charnel hound is about 20 feet tall and weighs about 35,000 pounds.