Dua-wurm
this rock-eating beast was native to the planet Cularin. Measuring up to three meters in length, it was named for the fact that it had two heads at the end of its neck, which it used to dig wide tunnels through the rocks which gave it sustainence. These creatures migrated to Cloud Mountain after the volcano erupted, where they found vast quantities of molten ores being brought to the surface. The dua-wurm fed by biting into the rock and leaving behind a saliva which was filled with acid. This broke down the rock and made digestion easier. When miners discovered Cularin's rich natural resources, the duam-wurm was considered a dangerous nuisance, since it ate the very ores that were being mined, and viciously defended its territory.