"Garlic Meat Beast" sounds like a good name for a lot of things. It would be a great name for a rock band. It certainly would make a nice euphemism for a part of the male anatomy, especially if its owner is an aficionado of garlic. Incidentally, the Japanese does not say "beast", but says "garlic meat monster". That would be an even better name for a rock band.
These burgers became available on July 26, these became available, though for some reason they are not being sold at the Burger King near where I used to live (Shin-Koenji). I guess that meat monsters simply are not welcome there.
The word "stamina" in Japan is a code word for "high in calories and fat" and it is applied to the meat monster pictured at the top. As you can see, it has three kinds of meat as well as garlic chips, though one is a grilled piece of chicken so that shouldn't lend too much of a load to the calorie total. Unfortunately, I could not get stats on this as it was't included in the nutrition information on Burger King's site. I'd wager, however, that it'd be best to skip dinner if you have the beast for lunch.