Nocturne Dragons are a strange breed. Whenever light strikes their bodies, they are frozen in whatever position they were in. This leaves them vulnerable and they rely on camouflage to keep themselves safe. They are often mistaken for statues when in this frozen state, but Nocturne dragons do not actually turn into stone. Rather, they merely idle until the sun goes down. At night, these dragons come to life, proving themselves to be powerful fliers, although little else is known about their true behavior.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Tellurium is very rarely seen in the Periodic Clan, be it at night or during the day; he changes his daytime hideout regularly on purpose, so that he's not disturbed in his slumber. Such a mysterious dragon is very interesting, at least to the gossips called Catalysts, but few members of the Clan actually try to seek Tellurium out, let alone talk to him. One of the reasons is, perhaps, that he constantly emits the foul stench of rotten garlic. The Catalysts claim that Tellurium is in fact a vampire hunter, who bravely ventures out of the Clan's territory to fight them every night—hence the smell, which could arguably help fend the undead creatures off. As it stands, with no substantial proof of Tellurium's exciting adventures, the odor mostly just fends off everyone else.