Specters identified as "Sith Warriors" manifested on Moraband, the original homeworld of the Sith. These ghost-like figures were created by both the Force Priestesses and the power emanating from the dark side of the Force. Their purpose was to assess whether Jedi Master Yoda was prepared to begin the necessary training in order to preserve his sense of self after death.
During Jedi Master Yoda's travels to Moraband, he encountered seventeen of these specters. The Force Priestesses, in conjunction with the power of the dark side of the Force, conjured them as part of a larger trial to determine if Yoda was worthy to train to retain his identity after death. The apparitions surrounded the Jedi Master, taunting him about his mission. After promising to reveal his whereabouts to the reigning Dark Lord of the Sith, the specters attacked him. This assault created ripples in the Force that ultimately alerted Darth Sidious to Yoda's presence.
The Sith Warriors made their initial appearance in Star Wars: The Clone Wars animated series during its sixth season. Corey Burton and Dee Bradley Baker provided their vocal performances.