Part of the string of insults hurled by the French Taunter in "Monty Python and the Holy Grail"
"You don't frighten us, English pig-dog! Go and boil your bottoms, son of a silly person. I blow my nose on you, so-called Arthur-king, you and your silly English K...kaniggets." ~French Taunter
A random concoction of an insult originating spontaneously from the two individual insults, bitch and pig. Denotes a fusion of the respective negative elements of the afore mentioned insults, that is, a bad attitude mixed with gluttony and lack of refinement.
Kasia, you're such a bitch-pig!