Here's a few behind the scenes photos from
Friday The 13th (1980) and
Friday The 13th: Part IV The Final Chapter (1984) of Tom Savini doing his work. The first is Tom doing some touch ups on young Jason Vorrhees, the next is Tom doing some work on Mrs. Voorhees head that will be used in the decapitation and the last is from
The Final Chapter, which is Teddy's head used with the knife impact.