Vomitrocious -as my friend, Jezziebelle, used to say.
The earliest appearance of the term McGangBang was May 26, 2006, on a page on Urban Dictionary devoted to the McGangBang.
User jenifurr wrote that it was "originally started at Daytona Beach ISB McDonalds" — but this version used two cheeseburgers and a spicy chicken sandwich (total of $3.21).
User McWayne posted on October 19, 2008, saying that it was made with a double cheeseburger instead of two cheeseburgers.