Dr Vladimir Demikhov successfully transplanted the head of a puppy onto the body of an adult dog in 1954.
Even the American magazine Time reported the experiment with grudging admiration, describing how the puppy's head alternately growled and snarled with mock ferocity, or licked the hand that caressed it.Edit: here's some bonus TV footage of said experiments.
"The host-dog was bored by all this but soon became reconciled to the unaccountable puppy that had sprouted out of its neck," their correspondent wrote. "When it got thirsty, the puppy also got thirsty. When the laboratory grew hot, both host-dog and puppy panted to cool off."
After six days, the bizarre hybrid died. But it had survived long enough to worry America, which was desperate to outdo the Soviets in all aspects of science and technology.