In addition to his acting career, Dunne has also co-written the Roxy Hunter franchise for Nickelodeon. The first two films, Roxy Hunter and the Mystery of the Moody Ghost and Roxy Hunter and the Secret of the Shaman were shot in 2005. These films spawned a successful franchise that has led to his co-writing the third and fourth installments in the series, Roxy Hunter and the Myth of the Mermaid and Roxy Hunter and the Horrific Halloween. He has also co-authored the novels for Penguin Books.