There are four varieties of demon cats:

Felis demonica margarita (demon sand cat, FDM), felis demonica chaus (demon jungle cat, FDC), felis demonica silvestris (demon wild cat, FDS), and the distantly related pardofelis demonica marmorata (demon marbled cat, PDM).

The original demon cats, FDMs, were intelligent and powerful, having demonic powers on top of feline talents. Some bred with talking sand cats and produced nephilimic talking sand cats. Others reproduced with normal creatures, and their young would lose intelligence and power over generations, culminating in dark powered sand cats. The religious claim that the FDMs were made by a mortal, and thus could not maintain a whole race over generations, but the scientific point out that any race breeding with unintelligent creatures would reduce in power and intelligence over generations--and that those breeding with intelligent creatures maintained a certain level of demonic power and normal intelligence.

These creatures, crafted by the bioalchemist Belinda Sage, were part of a complicated series of experiments. She had previously crafted FDCs, but they were never intelligent, merely being jungle cats with vile powers. FDSs, on the other hand, were an attempt at an intelligent race that failed, leaving behind only insane, wild animals with dark powers. Then, FDMs succeeded, so she moved on to trying breeding experiments with them, one of the byproducts of which was PDMs, which turned out to be unintelligent.

This could change depending on the current campaign.