9. Mia Goth - X
Ti West's recent hit horror film X starred Mia Goth as aspiring porn actress Maxine Minx, who turns out to be the sole survivor of the movie's ill-fated porn shoot, where the cast and crew are picked off by a horny elderly couple, Howard (Stephen Ure) and Pearl, living on the property.
And yet, as wasn't apparent to everyone while watching the film, antagonist Pearl is actually also played by Mia Goth herself under extensive prosthetic makeup, which unsurprisingly took hours to apply each day on set.
Goth gives a terrific dual performance in both roles, yet it's a surprising challenge for a low-budget production to saddle itself with, rather than just casting another actress in the role of Pearl.
Further to everyone's surprise, West secretly filmed a prequel to X, Pearl, which again starred Goth as a younger version of Pearl, to critical acclaim.
Better still, a third film in the series, MaXXXine, is soon set to start shooting, with Goth returning to the role of Maxine. That's quite the double act.