Friday the 13th Part 2
Almost everyone is familiar with the Friday the 13th series, but almost nobody has actually bothered to watch any of them all the way through. Fewer still have actually seen Friday the 13th Part 2.
It starts right where the first left off, though it is somehow five years later. And somewhere in the five years between 1980 and 1981 Jason Voorhees has managed to age properly (well, except for the whole being dead thing); he's now a proper adult-looking supernatural killer.
And while he starts with his trademark killings, he has yet to adorn his trademark hockey mask. Instead he makes do with work boots, clean blue overalls, and an elephant man-esque sack over his head.