In the 2008 movie, Eden Lake, which I just watched yesterday, this couple on a romantic weekend gets chased and tormented by a group of sinister teens. Throughout the movie, the heroine, played by Kelly Reilly, gets progressively muddier and muddier, as you can see below. She spends the second half of the movie caked in mud. Think of Leslie Bibb in See Spot Run, but in a horror movie!
Are there any other movies like this where the heroine is virtually unrecognizable at the end?