You might want to sit down for this one... two-headed sharks are very much a thing. But before you cancel your holiday beach trip for fear of a JAWS-style attack times two, know that the likelihood of a two-headed shark birth is 0.13 percent, and if the shark actually survives, its life will almost surely be brief. Quick—re-book those flights to Florida!
The biological phenomena of animals being born with two heads is called dicephalia. Although rare, two-headed animals have been documented since the 1800s. A producer named Todd Ray actually has the Guinness World Record for the largest collection of two-headed animals, including a two-headed goat and a two-headed albino hog-nosed snake. So what causes this defect—could it be man-made?