The most delicious and fattening of all McDonald's products. It can only be ordered from their secret menu, to access this secret menu you must punch a cashier in the face while shouting McMAC!! repeatedly. If the cashier is still alive, he must then (company rules) proceed to give you a McMac.
Cashier: Sir may i take your order?
Customer: why yes could i have a MCMAC MCMAC MCMAC!
Cashier: OMG WHY WOULD YOU PUN...
Customer: *jumps over register and continues punching Cashier*
Cashier: ok ok, here's your mcmac