Chaggrin

(From Planescape: Monstrous Compnedium Appendix II - 1994):

The chaggrin, or soil beast, is a grue from the Elemental Plane of Earth. An earth grue can assume the shape of a large mole, hedgehog, or humanoid. The latter, its natural shape on its own plane, is lumpy, wet clay, with an asy metrical and vicious face and small, feral eyes. On other planes it takes the form of a yellowish hedgehog I with a skull-like head. Although only 3’ long, an ea weighs 140-210 pounds.

Combat: In its hedgehog form the gme can merge into surfaces of natural soil or stone, emerging suddenly to surprise opponents (-5 penalty to their surprise rolls). The only clue to its presence is a damp, dark outline, faintly perceptible to careful observation. An earth grue loves to torment its victim. It attacks by digging its razor-sharp foreclaws into its prey (ld4+2 damage) and then clinging (an additional ld6+6 damage per round). In hedgehog form the gme inflicts Id4 damage per round in contact with unprotected flesh. 

Chaggrins are immune to earth-based/affecting spells such as earthquake, passwall, transmute rock to mud, stone to flesh, and the like. The mere presence of the gme within 40’ of such magic dispels the magic, even if the magic had been permanent. Magical items are not affected. 

Habitat/Society: Chaggrin scratch out a living from mineral veins, which they eat. They live in extended families that cooperate in limited ways or feud. Mates are stolen in violent raids. A chaggrin leaving its family or exiled never returns, capturing a mate of its own. 

Ecology: Earth grues eat valuable minerals. Higher elemental creatures exterminate them as vermin but sometimes enslave them as diggers __ or watchdogs. Some earth elementals eat them as delicacies.

(From Complete Arcane - 2004):

This strange creature resembles a mole the size of a hog, with long, filthy claws and beady, hate-filled eyes. It seems to be made of clumped “ soil and rock.

Caggrins, or earth grues, are magical corruptions of earth and rock, They are hateful and violent creatures that dig and burrow for no other reason than to damage the element that spawned them, but they especially like to slake their dusty thirst with © the blood of Material Plane creatures.

An earth grue is about 5 1 feet long and weighs almost 500 pounds. It can burrow though soil, earth, sand, rubble, or other loose material, but not through solid stone. Its voice sounds like rocks grinding together, Though they speak Terran, chaggrins are not talkative creatures.

To determine the type of spell object contained in an earth grue, roll d%: 01-70, resist energy; 71-100, nondetection.

Combat: Chaggrins like to lie buried in the ground, hoping to surprise foes passing overhead.

Sneak Attack (Ex): Ifa chaggrin can catch an opponent when he is unable to defend himself effectively from its attack, it can strike a vital spot for extra damage. Basically, the chaggrin’s attack deals extra damage any time its target would be denied a Dexterity bonus to Armor Class (whether the target actually has a Dexterity bonus or not), or when the chaggrin flanks its target.