15. Angela's Big Reveal - Sleepaway Camp (1983)https://www.youtube.com/watch?v=ADEM_IDN-iU
The Movie: Made at the height of the low-budget slasher film craze, Sleepaway Camp tells the story of a girl named Angela who, after surviving a horrific boating accident which killed her father and twin sibling, goes crazy and murders a bunch of unsuspecting campers.
The Legendary Scene: At the end of the movie, Angela is discovered holding one of the teen’s severed heads while standing naked, revealing herself to not only be the killer, but also that “she” has a penis, and is in fact Peter, her brother believed to be dead. Angela had actually died in the boating accident that day, and when her aunt gained custody of Peter, she raised him as “Angela”.
Had Angela merely been revealed as the killer, nobody would have been massively shocked, but this twist certainly took things up a few notches and allowed Sleepaway Camp a spot in horror history that it otherwise would never have attained.