Each Fever Wyvern carries a unique and very deadly disease on the spines of its tail. To make up for a lack of physical strength, the dragons use this disease to their advantage by poisoning prey and fending off attackers. The illness will quickly render victims helpless before eventually killing them. A Fever will track its prey until the target can no longer move. Usually a solitary breed, these dragons will only come together during mating season, and will flare out the brightly colored sails along their wings to help attract potential mates. Although it has been observed that the wyverns are nocturnal, they will often pick an open spot of sunshine to curl up in and sleep as the day passes by.

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.

This wyvern is the only one of its kind captured and kept alive. She attacked a town, killing several families. An experienced hunter returned home to find it destroyed, picked up a spine he found, and was infected by weakened residue on it. Barely surviving the resulting fever, the hunter became immune to the wyvern's disease. Once well, he promptly used a poisoned sheep to sicken the wyvern in return.

Caging the wyvern when she was too weak to do more than scratch him with her spines, the hunter now uses her as a source of venom for his arrow tips. Visitors are allowed to view her for a fee, cautioned against approaching too closely.

The wyvern is hardly content with her fate; she awaits the day when the hunter makes a fatal mistake and she can pay him back for her captivity.