Dark Jedi, also known as "Fallen" Jedi were Force-sensitives, frequently former Jedi, who chose to deny the light side of the Force and/or follow the dark side. Although "Dark Jedi" originally referred to a Jedi who had fallen to the dark side, it could also refer to uninitiated Force-sensitives who received no Jedi training but began their careers under another Dark Jedi. Others were simply dark-side users who did not follow the teachings of the Sith or other dark side organizations. In some cases, Dark Jedi also included "artificial" Force-sensitives who served the dark side.
These NPCs were not linked to any one planet and had the potential to spawn on any of them.
A Holocron , Petrified Avian Egg , DK-44 , a Stone Knife , a Crystal  and some unknown Weapon Components  were all listed as being looted from this NPC.
One player claimed to get approximately 3500 XP for killing one. 
One player stated that he killed 312 of these NPCs and got 1 holocron. 
A player claimed that two of these NPCs regularly spawn at some ruins at -1914 600 on Dantooine.