They are very similar to the Justrali, being gigantic Snakes about three metres in length, with a humanoid upper torso and arms, covered with scales. Their head is notably like that of a Cobra, complete with a large hood, giving them the identifier Cobra People. They also possess a powerful poison capable of inducing paralysis within minutes, and lasting for up to a day, though as they are capable of voluntary envenomation, a victim of their bite is not always poisoned.
Whilst all Kassistra have some hypnotic ability, it is generally only their priests who perfect this, using it to extract information and servitude both from prisoners. As with all the Snake People, the Kassistra are horrifically cruel and delight in these manipulations, particularly the staging of duels between two or more hypnotised prisoners. It is thought that the Kassistra were instrumental in bringing polylatreia to the Caarth race through their worship of deities such as Vermistra and Trabaten as well as the Demon Prince Sith, the creator and sole patron of the Caarth.
Unlike most Caarth creations, which were abandoned to the desert, the Kassistra are notable in that they have mostly escaped their masters, dwelling more as small family groups rather than communities with the Caarth citadels. However, since they too are cold-blooded, they must remain within the deserts and thus in the realm of their creators. Strangely, the Caarth do not seem too interested in recapturing their race and leave them relatively alone - the reason for this is unknown.