Jason Voorhees is a character from the Friday the 13th series. He first appeared as the young son of camp-cook-turned-killer Mrs. Voorhees. Jason was not originally intended to carry the series as the main antagonist. The character has subsequently been represented in various other media, including novels, video games, comic books, and a crossover film with another iconic horror film character, Freddy Krueger.
The character has primarily been an antagonist in the films, whether by stalking and killing the other characters, or acting as a psychological threat to the protagonist.
The trademark hockey goalie mask did not appear until Friday the 13th Part III. Since Friday the 13th Part VI: Jason Lives, filmmakers have given Jason superhuman strength, regenerative powers, and near invulnerability.