The Wurm is an old Norse name for a serpent like creature that has horns such as Laidley Worm, Lambton Worm, Loathly Worm and Stoorworm. Generally they had no limbs or wings like their Dragon cousins. Such Wurms also include Nidhoggr a winged Wurm that lived in the Underworld and was a bringer of death.
Although many aspects of today's Dragon come from the Wurms of norse mythology, the majesty, wisdom and gracefulness are qualities that lie in winged serpents of other traditions. The word Dragon comes from the latin word 'draco'. together all aspects of monstrous serpents have been combined to create the modern version of the Dragon that we are familiar with.
Many Wurms lived on land, usually in dark and damp places such as swamps and were mainly predacious to animals and people. Unlike other types of mythical serpents, Wurms were always evil with intent and malicious. The Wurm had less supernatural abilites and was more easily dispatched by a hero than a Dragon. However the Wurm had the unique ability to move extremely fast and were very swift.