US cable network AMC has cast actress Danai Gurira in the role of Michonne in its zombie drama series \"The Walking Dead.\" Sunday night\'s Season 2 finale first featured the iconic character, who will be an important part of the series in Season 3, the network said. Michonne, a fan favorite from Robert Kirkman\'s comic-book series, is described as \"a mysterious woman armed with a sword,\" AMC said in a news release. Gurira has appeared on TV\'s \"Treme\" and \"Lie to Me.\"