It's called the "Mega Tamago" and has (as you can see) 3 beef patties, 2 strips of bacon, an egg, cheddar cheese, lettuce, a 'special' sauce and 3 buns. It is described on McD's Japan website as: "The Mega-Egg " Anyone want to be the first person to go to Japan and actually try and eat this thing? It looks huge but tasty!
