Neil is one of the grave robbers who appear in Tommy Jarvis' nightmare in the opening of Friday the 13th: A New Beginning.
Biography
Along with his buddy Les, they decide to dig up the grave of Jason Voorhees in the middle of a rainstorm, while Tommy watches. They eventually pry open the coffin and marvel at Jason's worm-eaten body. The killer suddenly springs to life and stabs Neil in the gut with his machete, taking out Les with a screwdriver to the throat.
As the entire thing is revealed as a dream sequence, it's very likely that he never existed in reality.
Gallery
Neil's death at the hands of Jason Voorhees