Many get scared when they shape shift. It is said, never piss off a norn. Those that do, end up shredded like a piece of meat done by a hungry animal. After the awakening of the dragon of Drakkar Lake the Norns were forced to relocate further south, where they engaged in hostilities with the Dredge over territory. They were pissed about it, but they knew that they couldn't handle a dragon on their own. It was too big for them alone and they're not too thrilled to work together. The Norn were first introduced in the Eye of the North chapter of the original Guild Wars