Hellfire Wyverns are so named for their foul tempers and fiery visages. Their social structure places all females above all males, due to superior physical characteristics and violent dispositions. Forced subservience of the males causes them to become vicious, petty, antisocial, and passive-aggressive compared to the aggressive and social females. However, orphaned hatchlings raised by foster parents of another species can develop surprisingly even tempers and mellow dispositions, proving that their defining unpleasant nature is, in fact, a learned 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.

Otar the Mad is the quintessential hellfire.  Petty, jealous, paranoid and an awful temper to boot.  The females under the scroll-holder's care much prefer Nelduin's (marginally) better temper.  This leads Otar to being frustrated in his inability to even keep non-mating company of any of the females.  He doesn't resent Nel over this, rather he looks up to him like an older brother or father.  They still fight but it is negligible at the end of the day.