The Yam'rii are a mantis-like alien race from the planet called Huk. The Yam'rii are carnivorous and extremely strong. They are known as stealthy hunters and have a good deal of technological aptitude.
In the years before the Clone Wars, the Yam'rii were at war with the Kaleesh from the planet Kalee after the Yam'rii tried to enslave the species. This war only ended after the Galactic Republic intervened by sending a strike team of Jedi to Kalee, as the Yam'rii convinced the Republic, with the aid of their Neimoidian allies in the Trade Federation, that the Kaleesh started the war. Little did the Yam'rii know that by doing this, they wound up causing a young Kaleesh warrior to join the early Confederacy of Independent Systems, General Grievous. Following this, the Yam'rii began enslaving the Kaleesh in secret, using them to build up their slave empire.