Succulus

Nicknamed the crimson steel cruncher, a succulus looks like a wild boar with a grayish-black woolly coat, a bristly mane down its spine, curved lower tusks up to 12 inches long and small rust-red eyes.

Like a rust monster with narrower tastes, it eats only crimson steel, the curse-warding red metal, and seedmetal, and can smell them from 90 feet. Any such metal it touches with a successful attack crumbles at once into powder it can lap up, and weapons of these metals that hit it suffer the same fate. Magic items get a 10% chance per plus to survive (a +2 blade or armor resists 20% of the time); other magic items made of these metals count as +2. Each meal, large or small, takes one round to eat.

It is too smart to be distracted by a few tossed crimson steel spikes and goes straight for whoever carries the metal, often charging while using its spike curse-born gift so the victim will strike back with the very item it wants.

A succulus nearly always travels with wild swine, and each encounter has a 5% chance of including a youngster at half strength. The herd senses it is different but accepts it, since its deep rooting for metal turns up tubers the boars love. It ranges widely and eats raw ore but prefers forged metal. First found in caves under the woods of a forested coastal realm, it has spread through the cursed lands of the frontier coast. Some blame that realm's druids, who distrust lifeless stuff like stone and metal.

Its flesh is saturated with heavy metals and inedible. Two crunchers always breed crunchers; a cross with an ordinary swine has only a 5% chance. Cured hide yields a tough leather that makes armor equal to studded leather (AC 7). Raised from a young age and trained, one could locate deposits of the red metal, though feeding it would cost a fortune.