There are 8 unique and utterly dissimilar earth dragons. They are mythical in scope and rarely interact with the world of mortals.
Kun Hong is a long and serpentine dragon best known for consuming various elementals, living creatures, spells, towns, and other denizens of the material world, and then combining them with his strong earth magic into certain enormous crystal formations. He goes through long periods of slumber, and currently sleeps deep in the earth.
Bouever Inhabited a bubbling hot swamp near the center of the world for many thousands of years. In the bubbling hot mud he would swim, splash, and play, and as he passed through the hot mud, magic would slough off. Over time, the concentration of magic became so strong that it began mutating all of the inhabitants of the swamp. Like a compost pile, it served as a massive breeding ground for new species, and a steady stream of them left the swamp and entered the material plane. Bouever takes the form of an enormous flat fish with skin like pebbled granite. He has long, flexible whiskers, and bushy stone eyebrows. He is generally friendly, although largely unconcerned with human affairs.