20 Best Performances In Horror Movies

The Exorcist might just be the scariest horror movie ever made, and a lot of that comes down to the film's bewildering special effects - the stairs-running, head-spinning madness of it all.

But amongst the gore and violent scares, The Exorcist's secret weapon comes from the raging performance of child star Linda Blair, who plays ill-fated Reagan MacNeil. From the vulgar taunts to the physical contortions, the switches between innocent victim to embodiment of evil, Blair commits herself to every aspect of Reagan's unpredictable character trait and volcanic personality change.

Blair shouldn't get all the credit, however - although her physical performance is truly remarkable in its own right - as her voice when possessed was actually provided by Mercedes McCambridge, whose vocal work, mixed with Blair's contorting, bed-ridden portrayal of possession, made Reagan the horror icon she is today.