During the heyday of the sideshow, performers came in several categories. There were those who were born as physical oddities, those who became so through injury, those who merely displayed an exotic background (which was usually exaggerated), and those who worked hard to perform amazing feats. Martin Laurello had no exotic background, but he combined the other three categories to become "the Human Owl." He could turn his neck until his head was completely backwards!
Laurello was born flexible, and was a contortionist in a circus act. There is some evidence that he suffered an injury that left his neck even looser than before, and while recuperating, he trained himself to turn his head 45 degrees, then 90 degrees, then 180 degrees, although the last part needed his hands to achieve. Laurello worked for Ringling Brothers, then at Coney Island, then for Ripley's Believe It or Not. He was also an activist inside the community of human oddities, working to change the demeaning language of his time away from calling such people "freaks." Read about the life of Martin Laurello at Mental Floss. The article includes a video of Laurello doing his thing. -via Strange Company
(Image source: Txemari. (Navarra).)