Trolls (Troll Hunter)

Trolls appear as the main antagonists of the Norwegian horror "Troll Hunter" and are based on the Trolls of Norse legend, being much larger than humans and acting akin to intelligent but aggressive animals - they are also a collective term for many connected species (just as in mythology).

The most prominent trolls in the film were the forest trolls, the cave trolls and the climatic Jotun - all of the trolls in the film are exceptionally dangerous beings with the strength and mass to kill humans with ease, though most seemed to prefer hunting animals or livestock when not exploring the remote areas of Norway.

The titular "Troll Hunter" pursues trolls that have strayed to close to human habitats and kills them using special lights designed to mimic the sun's radiation - this causes a violent reaction in even the largest of trolls, seeming to turn them to stone (however unlike in the myths it is explained more as trolls turning into bone, due to calcium).

Another blend of science in the otherwise fantastical film was the explaination that the trolls of Norway were becoming increasingly violent and bold due to being infected with rabies.

Trolls in the movie (again like mythology) could smell the blood of Christians and went into a berkserker fury upon sensing them - this was explained by the director of the movie in the sense that Trolls see Christians as invaders who stole the reverence and worship the Norse used to have of Trolls and forced said Trolls into the wilderness as a result (trolls in mythology are also said to find the noise of bells to be painful, hence the church bells of traditional Christian churches were a source of ire for the already short-tempered beasts).

Jotun
The Jotun was the largest and most powerful troll in the movie and served as the climatic villain, it is based on the ice giants of Norse mythology and stood at roughly 625 ft in height, easily dwarving every other troll in the movie.