- "But while the Mok'tagar can assume many forms and guises, including human, they can always be recognized by others of their kind due to the lack of a soul."
- ―Rupert Giles[src]
Mok'tagar Demons were a trans-dimensional species of demon.
A young, female Mok'tagor demon named Kathy Newman disguised herself as a human so that she could attend UC Sunnydale. However, her parents disapproved of this and her father, Taparrich, sent two of his kind to find her. Buffy Summers, Kathy's roommate at the time, became a victim of several rituals preformed by Kathy to steal her soul so that Kathy would not be recognized by her father's henchmen. Because of the rituals preformed on Buffy and her superhuman strength, Taparrich's henchmen deduced she was Kathy and sent for Taparrich to collect his daughter. However, Buffy's watcher, Rupert Giles, preformed a spell that reversed what Kathy had done to her. This allowed Taparrich to recognize Kathy and take her back to his dimension.
Mok'tagar Demons resembled veiny skinned humanoids with glowing blue eyes and sharp teeth.
They had several abilities such as superhuman strength, teleportation, levitation, inter-dimensional travel and uncanny regenerative abilities. For example, Kathy's loose toenails kept growing after being cut. Despite their ability to change forms, such as human, Mok'tagor demons could recognize each other due to the lack of a soul, though, these demons were also known for performing a ritual to remove the souls of humans and take it as their own to avoid detection.
They also spoke their own language and lived thousands of years to the extent that a Mok'tagor Demon aged 900 years was considered young.
Interestingly, this specie, although a dark magic practicioner, seems to not want attack humans, contrary to others demons. An example is demonstrated when Tapparich find his daughter, and doesn't attack Buffy, Xander or Oz. He only intimidates them. It is plausible to think that this specie prefers to avoid interaction with humans.