Troll Hunter is a 2011 found footage "mockumentary" horror film written and directed by André Øvredal. The story follows a group of students making a documentary about a supposed bear poacher, Hans, who in reality turns out to have been hunting trolls, working for a secret section of the government called the TSS, or "Troll Security Service".
Troll Hunter is a horror film for anybody who wants horror in the passenger seat to comedy (and gorgeous scenery of the Norwegian countryside), as it has an emphasis on jokes and lightheartedness over actual terror. It has tense moments and it has its share of violence, but overall is a funny faux-documentary with plenty of ribbing on the Norwegian government.
To date, it's one of my favorite films solely because it fits my favorite niche: horror-comedy. Nothing soothes my soul like being able to laugh at dark, violent moments. Movies like Rocky Horror Picture Show (1975) and Krampus (2015) let you indulge in horrific scenes without all the serious baggage, which isn't why I'm watching a movie. I'm watching to feel good.
Much of Troll Hunter's lore and plot come from actual Norwegian fairy tales and mythology incorporated into modern, realistic settings. For instance, the trolls in the film die when exposed to sunlight, an ancient belief on how to kill a troll (seen in The Hobbit: An Unexpected Journey (2012)). Hans the troll hunter accomplishes this via huge UV spotlights attached to his truck.