Pamela Voorhees is the original slasher of Friday the 13th . She is the mother of the slasher mostly associated with these movies, Jason Voorhees.She lived in Camp Crystal Lake, where she worked as a counselor. However, her son Jason was thrown into the lake where he drowned. All the other counselors were too busy having sex to notice Jason's muffled screams.Thus, Pamela grew hateful and resentful of teenagers, and decided to kill all teenagers entering Camp Crystal Lake. In the first film she killed as many camp counselors as she could until she was stopped by Alice, the only surviving camp counselor left at the end of the first film. Alice then decapitated her.After her death, her son (who didn't drown, and is an adult now) continued her mission to kill all teenagers in Crsytal Lake. The spirit of his mother commands Jason, and inspires him to kill.In Freddy Vs Jason , Freddy Krueger uses this to his advantage by posing as Pamela and commanding him to kill the teenagers in Elm Street, so that the fear brought by the killings can make him kill on his own.