Folklore often finds its way into horror, but the results tend to be mixed. Some legends are simply too specific to one culture to translate well to another, losing some of their power. But giant, rampaging monsters? Yeah, that’s something that’ll work pretty much anywhere.
Trollhunter follows a group of college students investigating a suspected bear poacher. Hoping to use him as the subject of a a documentary, they track the hunter down only to be refused an interview. However, after following him into the woods one evening, they discover he is after far bigger game than the local wildlife.
Trollhunter works for a number of reasons why most found footage movies fail. The actors feel natural in their roles and have a decent enough reason for filming everything. The hunter, played by Otto Jespersen, is a surprisingly subtle and complex character–so much so that I wouldn’t have minded an entire film centered solely around him.
The trolls also prove to be a compelling presence in and of themselves. They’re treated far more as unique animals to be managed rather than supernatural monsters. Certain traditional qualities–like aversion to sunlight–are given scientific explanations, leaving their hatred for anything Christian as the only part that doesn’t quite work. The filmmakers also chose to create several different species of troll rather than relying on one type. This adds some welcome variety and tension to the encounters as one is never quite sure what to expect. The special effects are decent for the most part, but they do look weaker outside of the darker and infrared scenes. Still, it’s not overly distracting.
The film also balances humor with its more horrific elements surprisingly well for a movie in its sub-genre. Quiet visual absurdities are used to great effect, fitting in far better with the false reality presented than any one-liner could. That said, the real-life footage snippet at the end is fantastic, perfectly fitting the dry bits of comedy that preceded it.
Overall, Trollhunter is one of the best in its category. The unique setting and choice of monster would have helped set it apart on its own, but the care given to how the creatures fit in into the world puts it among the most compelling movies of its kind.
The Third Eye Opened 
I laughed my ass off watching this movie with my teenage sons. The funniest moment is when Hans comes running out of the forest yelling, “Troll!” I like your statement: “They’re treated far more as unique animals to be managed rather than supernatural monsters.” I read that the trolls hatred of Christians comes from Norwegian mythology.
I wrote a short essay on Trollhunter called “Reason, Courage, and Intolerance.” If you would like to read it, here is the link: https://christopherjohnlindsay.wordpress.com/2015/05/03/troll-hunter/ I am open to any helpful feedback.