Horgar

Resting, a horgar looks like a lava formation; moving, it resembles a gigantic black slug of rock. Its oblong body wears a hide of true stone up to five feet thick, cracked into plates that grind and slide as it travels, with a softer stony lump of a head at one end.

Hot acid seeps between the plates, giving off an ammonia-like reek that stings eyes, nose and mouth. The only noise is stone scraping stone and the hiss of rock melting.

A horgar isn't aggressive, but it fails to notice most living things and plows on regardless of who stands in its path. Under attack, it simply tries to get away.

Its tunnels are hazardous. For three hours the walls deal 2d10 damage to bare skin, ignite wood or paper on contact, and heat touching metal enough to burn for 2d10 after one turn; they stay harmlessly warm for a day. Acid puddles deal 1d4x10 to flesh, and objects in them save vs. acid or are ruined.

Acid, fire and electricity cannot harm it, and striking it feels like hitting solid granite. Edged weapons deal half damage and save vs. crushing blow, and all weapons save vs. acid, so blades make two saves per hit; failing either destroys the weapon.

Cornered, it sprays acid from its head to 20 feet, then escapes at the first chance. Most creatures sensibly leave horgar alone.

Horgar live deep in hard rock, rarely near the surface or in soft stone. 'Horgar' is the dwarven name, 'storgin' the gnomish one, and both mean roughly stone-eater.

Their ancient digging has left thousands of miles of caverns, now weathered to look natural and home to many races. Some primitive peoples of the deep underworld worship them. Dwarves, duergar, drow, gnomes and deep gnomes use them as laborers, penning them in strong pits lined with glass. A dwarven handler, or horgarin, prods the beast with slender glass-covered spears slipped between its plates, which irritates it into moving away without injury. The shifting plates can snap a careless handler's spear, hence the dwarven proverb about a horgarin who has lost his.

Every 500 years a horgar buds off 2d10 eggs in a secret cave with a single entrance, losing 1 Hit Die per egg. The eggs radiate heat and ooze acid, hatching after two years as hungry 30 HD infants that gain 1 HD yearly until adult at 100 HD. A horgar is about a foot long per Hit Die.

Their digging produces breathable gases, fluids such as acid, and mineral deposits; without horgar, nothing could live in the deep underworld. Only wizards value their remains, using some parts in magic tied to earth, stone, tunneling and molten heat.