Aura of terror was an illusion spell, used by dragons, that enhanced or bestowed upon them the fear aura that naturally emanated within their presence. Its usage was particularly popular among young and juvenile dragons, who normally did not possess this innate ability.
When cast, this spell created an illusory effect that caused the dragon to appear older, more vicious and exceptionally battle-hardened. Others perceived the dragon as if it had longer spines, spikes, talons and fangs, along with scars and wounds that accompanied a dragon of advanced age.
It did not effect the dragon's appearance in terms of size or species.