Gravecrawler (CR 16)

Small Undead (Earth)
Alignment: Always neutral
Initiative: +2 (Dex); Senses: tremorsense, Listen +16, and Spot +2

AC: 17 (+1 size, +2 Dex, +4 natural), touch 13, flat-footed 15
Hit Dice: 25d12 (162 hp)
Fort +8, Ref +10, Will +16
Speed: 20 ft., burrow 20 ft.
Space: 5 ft./5 ft.
Base Attack +12; Grapple +8
Attack: Bite +13 melee
Full Attack: Bite +13 melee
Damage: Bite 1d4/19-20 plus 1d4 Constitution drain
Special Attacks/Actions: Calcifying aura, Constitution drain
Abilities: Str 10, Dex 15, Con -, Int 16, Wis 11, Cha 11
Special Qualities: Burrow, speak with dead, SR 30, turn resistance +6, undead traits
Feats: Alertness; Blind-fight; Combat Reflexes; Dodge; Improved Critical (bite); Iron Will; Mobility; Negotiator; Spring Attack
Skills: Balance +4, Bluff +14, Diplomacy +20, Escape Artist +16, Gather Information +2, Hide +34, Intimidate +2, Jump -4, Knowledge (history) +31, Knowledge (local) +31, Knowledge (undead) +31, Listen +16, Sense Motive +16, Spot +2, and Tumble +16
Advancement: 26-52 HD (Medium-Size)
Climate/Terrain: Any land and underground
Organization: Solitary, pair, or gang (3-4)
Treasure: Standard

Source: Monster Manual II

The gravecrawler, sometimes called the ancestor worm, is an intelligent, slug like undead with the power to turn flesh (dead or living) to stone. Gravecrawlers can be found in wilderness areas, but they are most often found in cemeteries, boneyards, and necropoli. There they slowly turn the surrounding dead bodies to a brittle stone that cannot be animated even by the animate dead spell.

A gravecrawler resembles a bloated, pale, segmented worm about 3 feet in length. Its face looks like that of a human or humanoid, except that it has no eyes - not even vestigial ones.

Gravecrawlers can communicate with the spirits of the dead they consume, and as such they often become repositories of local lore, history, and gossip. Because of this fact, some societies view gravecrawlers as beneficial creatures. Even those who consider them benefactors, however, tend to give their lairs a wide berth, since the presence of these creatures has a grievous effects on the living. Gravecrawlers are frequently sought out by those who seek hidden knowledge and lost bits of history, but they are hated both by necromancers and by corpse-devouring creatures such as the ghoul and the corpse gatherer.

Earth Subtype

This subtype usually is used for elementals and outsiders with a connection to the Elemental Plane of Earth. Earth creatures usually have burrow speeds, and most earth creatures can burrow through solid rock.