Norns are fey. This is important. They easily could have been listed as monstrous humanoids (taking after giants and hags) or outsiders (taking after night hags and other creatures of fate). But they are fey. That puts them outside the normal order of things—not quite mortal, not of the heavens, apart from outsiders and their battles over the Balance. Even gods likely fear the norns, because the most powerful norn grand dames measure and cut the threads of the deities themselves.
Do I need to even mention that norns come from Norse mythology? Or that they have analogs in Greek myths? Or that they stand as yet another example of the tripartite female goddess, which we’ve discussed before? In fact, any culture advanced enough to weave likely has tales of norn-like beings, so don’t feel the need to confine them to the snowy North, no matter what the climate icons say…
A mountain troll (see Land of the Linnorm Kings) promises to help craft an artifact necessary to slay a demon. His price is the theft of his golden thread of life from the norn who holds it.
A norn determines a squad of myrmidon adventurers is supposed to die. When their trireme rides out a typhoon she foretold would drown them, she is incensed. She sends Advanced skum assassins and a scylla after them, and if that fails, she takes matters into her own hands.
The Pattern Weaver is a famous giant woman who lives in the Lake of Pines, tended by jorogumo servants who help her with her weaving. (Their alignment differences matter little; the spider-women have served out of custom as long as anyone can remember.) She does not believe in heroes—their distinctive threads snarl the Pattern—and when she is not at her loom she hunts those who know not their place—rogues, ninjas, and tengus in particular.
—Pathfinder Bestiary 3 202