Warwick Davis is joining the cast of Star Wars: Rebels, we learned at the Rebels panel at Star Wars Celebration Orlando. According to Dave Filoni, Davis auditioned live onstage at Star Wars Celebration Europe, though Filoni didn't realize what was happening at the time. They showed a clip of that, and then brought out Davis, announcing that he'll be playing a character who has never been "seen on screen" in Star Wars before: Rukh, Thrawn's bodyguard.
"I needed someone creepy to play him," Filoni said. "Someone sneaky and devious."
They also showed an image of Rukh, which you can see below:
UPDATE: Due to auto-correct error in our communication with on-the-scenes reporters (we swear!), this article originally listed Davis's character as "Rhook." We apologize for any confusion. Also, shut up, jerks.