Opaali Theelins are a subspecies of Theelin. Like Theelins, Opaali have brightly colored hair and often have artisic personalities. What sets them apart from normal Theelins is that Opaali Theelins always have a tail and spots of Radiant Pigment on their skin.

While the hereditary mechanisms of the spots are not yet fully understood, their patterns seem mostly random, while their colors seem to be mostly inherited from an individual's maternal lineage.

Opaali Theelins live up to about 100 years. However, since aging starts later and initially progresses slower than for humans, they easily become 70 or 80 in good health.