The IG-100 Magnaguards

The IG-100 MagnaGuard, also known as the Self-Motivating Heuristically Programmed Combat Droid, was an advanced type of battle droid that was used during the Clone Wars as bodyguards of General Grievous, as per Count Dooku's order as well as being specialized infantry on the battlefield. After the InterGalactic Banking Clan secured Grievous's services as an enforcer, they refused to hire his Kaleesh, and thus the cyborg general demanded a cadre of "more intelligent battle droids" to serve him. The construction of the MagnaGuards was then commissioned for Grievous's service, though the Jedi-killing droids were also occasionally employed to escort Count Dooku himself.