The McWhopper was a sandwich that New Zealand creative director Tom Paine thought of. On September 21 2011, Tom Paine had talked to CCO Josh Moore about the idea of the McWhopper and then Josh Moore had figured out a way to talk to a Burger King client about the Idea. Then the three created Mcwhopper.com which had a 3 minute film talking about what the Mcwhopper was and how it was gonna top all burgers in the world and how they wanted to propose the Idea.
Thanks to LBBOnline for helping me on the info about the Mcwhopper