Franz Xaver Messerschmidt (1736 – 1783) was a German-Austrian sculptor known for his "character heads" – busts with extreme facial expressions.
He started out as an academically trained sculptor doing normal portrait commissions.
But then the work dried up, he lost his teaching position, and he suffered a mental malady that they called "confusion in the head."
He also suffered a stressful abdominal problem. When he pinched a rib to distract himself from the pain, he noticed that he winced in interesting ways.
(Video Link) TV's classic fitness guru Jack Lalane (1914-2011) had a passion for extreme faces too, but for different reasons. In this video, he demonstrates a "face workout" that everyone can do to keep the facial muscles tight and young.
Wikipedia on Franz Xaver Messerschmidt