Friday the 13th

A 1980's horror film about a woman, Pamela Voorhees, who saw her son drown at Camp Crystal Lake, and went crazy killing all of the counselors several years later for neglecting her son, then was decapited by the last surviving counselor. In later sequels her 'dead' son returns weilding a burlap sack and any pointed object...and later a hockey mask and machette to kill anyone who returns to Camp Crystal Lake, or anyone at all for that matter, as revenge for killing his mother. Has 11 sequels, including a battle between him and Freddy Krueger of the 'Nightmare On Elm Street' series.