Jimmy Darling, played by Evan Peters, is one of the main characters in American Horror Story season 4, Freak Show, and he’s actually based on a real-life figure with a similar physical condition. The fourth season of American Horror Story, as the title would imply, focuses on the last remaining “freak show”, or in current-day terms, “side shows” of the 1950s. This particular traveling carnival is led by Elsa Mars (Jessica Lange) and features many of the usual returning cast members for whom the horror anthology is known, including Sarah Paulson and, of course, Peters.

https://screenrant.com/jimmy-darling-ahs-freak-show-character-based-inspiration/