A Troll is a fearsome member of a mythical race from Norse mythology. Originally more or less the Nordic equivalents of giants, although often smaller in size, the different depictions have come to range from the fiendish giants – similar to the ogres of England (also called Trolls at times, see Troller's Gill) – to a devious, more human-like folk of the wilderness, living underground in hills, caves or mounds. In the Faroe islands, Orkney and Shetland tales, trolls are called trows, adopted from the Norse language when these islands were settled by Vikings.
Nordic literature, art and music from the romantic era and onwards has adapted trolls in various manners – often in the form of an aboriginal race, endowed with oversized ears and noses. They are often depicted with tails and hairy ears, similar to the ears of lynxes.The meaning of the word troll is unknown. It might have had the original meaning of supernatural or magical with an overlay of malignant and perilous. Another likely suggestion is that it means "someone who behaves violently" In old Swedish law, trolleri was a particular kind of magic intended to do harm. It should also be noted that North Germanic terms such as trolldom (witchcraft) and trolla/trylle (perform magic tricks) in modern Scandinavian languages does not imply any connection with the mythical beings. Moreover, in the sources for Norse mythology, troll can signify any uncanny being, including but not restricted to the Norse giants (jötnar).
- Trolls have been either seen or mentioned in all the Harry Potter books except The Half-Blood Prince.
- A troll was seen in Harry Potter and the Philosopher's Stone and mentioned in Harry Potter and the Deathly Hallows Part 1.
- Trolls appear in numerous Harry Potter games, based on the films and LEGO sets.