Contortionist n. One who makes or practices contortions; especially, A gymnast who is able to twist the limbs into positions impossible for normal people to achieve.
... an Acrobat and Society Contortionist made such a fuss that in the end I had to take his card in to the private office. Mr. Quhayne was there talking to a gentleman whom I recognised as his brother, Mr. Colquhoun. They were engrossed in their conversation, and did not notice me ... — The Swoop! or How Clarence Saved England - A Tale of the Great Invasion • P. G. Wodehouse