Fenrir

thumb|300px|Fenrir and Naglfar on the [[Tullstorp Runestone. The inscription mentions the name Ulfr ("wolf"), and the name Kleppir/Glippir. The last name is not fully understood, but may have represented Glæipiʀ which is similar to Gleipnir which was the rope with which the Fenrir wolf was bound. The two male names may have inspired the theme depicted on the runestone.]] thumb|right|An illustration of an image on a bracteate found in Trollhättan, [[Västergötland, Sweden. The image is considered a depiction of Týr tricking Fenrir. Drawing by Gunnar Creutz.]] alt=|thumb|Odin and Fenris (1909) by Dorothy Hardy

Fenrir (Old Norse 'fen-dweller') or Fenrisúlfr (Old Norse "Fenrir's wolf", often translated "Fenris-wolf"), also referred to as Hróðvitnir (Old Norse "fame-wolf") and Vánagandr (Old Norse 'monster of the [River] Ván'), is a monstrous wolf in Norse mythology. In Old Norse texts, Fenrir plays a key role during the events of Ragnarök, where he is foretold to assist in setting the world aflame, resulting in the collapse of humanity and society, and killing the god Odin.