Stop your Supergirls and turn off your Lanterns . The most interesting character from the DC Universe getting their own new story could be Matt Hagen, aka Clayface (Tom Rhys Harries), who just made his debut in a brand-new and undeniably gross trailer. Be warned: those of you who are somewhat squeamish and prefer to avoid body horror might want to look away now. Directed by horror aficionado James Watkins ("Eden Lake," "Speak No Evil"), the new film — from a script penned by Mike Flanagan ("Midnight Mass," "The Haunting of Hill House") and Hossein Amini — will shine a light on one of Batman's longtime foes and how he came to be. Almost akin to the Joaquin Phoenix-starring "Joker," "Clayface" is an origin story introducing us to Hagen, an aspiring actor whose life is changed forever when a gangster's attack leaves him permanently disfigured. In an effort to address the matter, Hagen turns to science, transforming himself into clay and giving himself the ability to alter his appearance.…