Lahzar
From Wookieepedia, the Star Wars wiki.
Lahzar was a being allied with the New Sith Empire near the end of the New Sith Wars. Three hundred Jedi Knights under Lord Valenthyne Farfalla defeated him on their way to the Sixth Battle of Ruusan.
Farfalla described Lahzar as "treacherous," presumably meaning that he had once pledged his support to the Jedi.
