Johnny Knoxville has announced via Facebook that his wife, Naomi Nelson, is pregnant with their second child. The "Jackass" star said he and his wife are "having another little bambino in the fall," UsMagazine.com reported. "My 15-year-old daughter Madison is very excited about it," Knoxville wrote on his official Facebook page. "And her 16-month-old little brother Rocko has, well, no clue. Wahoo!" The couple wed last year. Madison is Knoxville's daughter from a previous marriage. In addition to starring in the "Jackass" TV show and movies, Knoxville has also acted in "Men in Black II" and "The Dukes of Hazzard."