When we think of two headed animals we might presume to think of Greek mythological beasts, but Soviet research in the 1950's and 60's showed us otherwise.
Vladimir Demikhov was a Soviet scientist who became known as a pioneer in the field of animal organ transplants in the mid twentieth century. His early work involving successfully transplanting organs between animals, predominantly dogs (which most of his research was geared to).
But that wasn’t enough for Vladimir.
By the late 1950's Demikhov had successfully transplanted the head of a dog onto another living dog. Both dogs responded initially, but the attached dog's head suffered tissue degeneration quickly and died after a few days.
Throughout the course of his research, Demikhov attempted over twenty times to create the two headed dog with not much success at all.
His work did inspire other scientists in his field to take on similar endeavours, such as Dr. Robert White, whose claim to fame was successfully transplanting the head's of monkeys.