The Abomination of Zhirrak

This alien thing has an oblong body of stony flesh ringed by three dead white eyes, lidless and pupilless. From its crown rise three taloned arms that bend at two joints, and beneath each eye a shorter arm ends in a slobbering mouth. Bands of light and shadow swirl over its hide; up close they become the faces of dwarves, twisting in agony.

It swims through dirt, sand, mud, stone and metal alike, sensing vibrations while buried and even the heartbeat and breath of someone standing still. Its favorite move is to burst up beneath prey like a pike taking a fly, giving foes -5 to surprise.

Its six limbs can strike six targets but usually focus on one or two. Each claw deals 2d4+4, and two or three claws on one victim rend for an extra 4d4+4. A mouth bites for only 1d3 but holds on, then automatically deals bite damage and drains one life level each round, as a wight does, until released. Tearing a mouth off means hitting AC 5 to grab the arm, then making a Bend Bars roll at +20% (96 or more always fails); the victim takes 2d6 as it rips free. A slashing called shot (-4 to hit, -1 initiative) dealing 10 or more points in one blow cuts an arm off; weaker blows to an arm do nothing. A severed arm's mouth keeps biting and draining. Someone drained of every level becomes a dry husk, dead forever, and a dwarf slain so adds his own tormented face to the creature's skin.

The Abomination regains 3 hit points a round, and lopped limbs keep fighting (movement 6) until the body dies. Spells that beat its magic resistance are still reflected, as by a ring of spell turning. Mundane acid, poison, lightning, fire and frost have no effect; magical versions and breath weapons deal half damage on a failed save, none on a success. It can be hurt only by +3 or better weapons, and piercing or slashing ones inflict only their plus, adding the wielder's Strength bonus.

It dies only in its home dimension. Brought below 0 hit points elsewhere, it fades home and rests 2d6 hours before returning. To destroy it for good, reduce it to -20 hit points on its own plane and sprinkle what is left with holy water and with dust ground from its controlling amulet.

Ages ago the mad god of the derro made it for Haldur Coppergrip, a dwarf whose lust for a legendary royal axe made him a traitor and a killer. The god gave him a talisman to command it; as the god intended, the talisman failed, and the Abomination ran wild.

Its taste for minerals suggests it was once a xorn warped by the derro god's magic. Above all it hungers for life force, especially that of dwarves.