The phrase 'meal of the beast' can be used to describe any meal (usually fast food) that comes to a total of $6.66. The meal described with the phrase can vary from place to place.
The Ultimate Meal of the Beast:
Carl's JR. Double Bacon Western Cheeseburger (medium). This meal always comes to a total of $6.66 and is arguably the most satisfying and delicious fast food meal ever devised by mankind.