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.

Utaruun is an opportunistic hunter, quietly stalking his prey while spreading his disease through the air until the poor creature succumbs. This illness, which he affectionately calls the "Frenzy Virus", is viewed by Utaruun as a part of himself, yet also a separate entity. When asked to elaborate, he simply laughs and claims that only he can understand his relationship with the virus. Described as eccentric by other dragons and humans alike, Utaruun will sometimes converse with the Frenzy Virus, either aloud or within his mind.

Utaruun prefers to nest in the canopies of Galsreim's western jungles, never staying in one place for very long.