Mescall was behind the Dumb Ways to Die campaign for Metro Trains Melbourne. It became a worldwide sensation which set a new record for award hauls at the Cannes Festival of Creativity and spawned a whole stack of run-on content, from apps to merchandise and even a hit song. He founded Smart alongside Ben Lilley and Ash Farr, which was bought by McCann in a reverse takeover in 2011.
In June 2014 he was promoted to global ECD for McCann WorldWide and relocated to New York.
