Wyrms
Living deep within the Abyss, little in known about these gargantuan predators. They are reptilian creatures, with a long snakelike body about the length of a school bus. None know how they came to Denon, or if they were a native of the planet when it was green and full of life. What is known, is that they are dangerous predators and fiercely territorial.
Habitat
Wyrms are known to tunnel through the lower levels of Denon. By passively sifting through the many chemicals in the air and absorbing those needed for napalm into separate "venom sacks", they are able to eject the chemicals at will through separate holes in their mouths where the chemicals then mix in front of it and are used to melt the metal of the abandoned cityscape. As they create these tunnels, the wyrms naturally reinforce the walls with the melted metals that they create, leaving thick supports in their wake.
Due to the natural melting point of metal versus stone, wyrms stay within the confines of the lower city, never tunneling into the stone foundation that the city planet rests on. Their need for the chemical clouds also limits their territory to the lower levels where clouds of it are more common, though they will travel some ways upwards to hunt.
Diet
As a large predator, wyrms will consume anything larger than a big dog that wanders into it's territory. (Some specific species will be listed and hopefully linked once I have written them)
Mating
Wyrms mate for life, and will raise nests of one to two children. Due to their role as top of the food chain and the strain their appetites' can put on the ecosystem, the number of wyrms is low compared to many smaller predators.
Folklore
Numerous legends surround this species. Some consider them to be beings of the afterworld, souls of cruel men come back tp haunt the lower levels of Denon. Others still consider them the king of beasts, and the rightful ruler of Denon. Among the Amavikkan, the wyrm are nothing more than animals. Except that is, for Leia. Unlike on Tatooine where Leia is a Great Krayt dragon, rumored to have grown wings ant taken to the sky, the local Denonites consider Leia to be an ancient wyrm, the largest and grandest of them all.