The protoceratops was a sheep-sized dinosaur which once roamed the land in what is now Mongolia. The four-legged creature had an enormous head and a parrot-like beak, which early fossil hunters likely mistook for the remains of a griffin — a mythical beast said to have the head of an eagle and the body of a lion. Even today, protoceratops fossils can be found all over the Gobi desert, and given the skeletal form of the animal's fossils, it's easy to see how the griffin theory was originally conceived.