Scarlett Johansson and "12 Years a Slave" star Lupita Nyong'o are in negotiations to join the voice cast of Jon Favreau's "The Jungle Book" at Warner Bros. Pictures. The live-action/CGI combination adaptation of Rudyard Kipling's beloved novel follows a young boy named Mowgli raised in the wilderness by a pack of wolves, a bear and a black panther. Scarlett Johansson is in early talks to voice secondary villain Kaa, a python who eats other animals after hypnotizing them.