Jack Black Joins the Cast of Borderlands as the Voice of Claptrap Jack Black Joins the Cast of Borderlands as the Voice of Claptrap Posted on The cast of Borderlands continues to grow, and they keep grabbing A+ talent for this cast. Today, according to Deadline, we got the announcement that Jack Black would be joining the cast as the lovable robot Claptrap. This movie is turning into a The House with a Clock in Its Walls reunion tour because Eli Roth directed that movie and Cate Blanchett started. "I am so excited to reunite with Jack, this time in the recording booth," Roth commented. "Claptrap is the funniest character in the game, and Jack is perfect to bring him to the big screen."