Demoniacs were tall and thin, with long, narrow skulls, leathery wings and long tails. They had red, glowing eyes and twin horns on their head. They had long fingers tipped with sharp claws. Demoniacs had scales in a variety of colours, ranging from jet-black to a deeper red. Despite having wings, Demoniacs could not fly outside of Gehenna, due to a combination of a lack of thermals, a thicker atmosphere and lighter gravity. Demoniacs could survive in areas of very high smoke, due to the conditions on Gehenna. They were warm to the touch. (PROSE: Mean Streets)
In Demoniac culture, someone who is offered food and drink is considered a guest, and is therefore safe from harm. When dealing with humans, they generally took the names of demons from mythology, though whether this was an attempt to impress humans or simply a type of joke was unknown.
Though Gehenna and the Demoniacs were discovered by explorers from Earth, it was also believed that (like the Dæmons) they had come to Earth in its early history and influenced their perception of Demons.
Many Demoniacs moved off planet to look for new opportunities, becoming scholars, soldiers and administrators. In more human-dominated areas of the Galaxy, they were generally forced to become criminals. Lucifer of Mega City was a Demoniac of the second type. (PROSE: Mean Streets)