>>15838648there are two types of "undead" people north of the wall. the first are the wights (i think they are called) who are reanimated dead, and people touched by the whitewalkers.
the whitewalkers (usually referred to as the others) are a race of ancient beings who had dominated the world a long time ago... nobody knows anything about them other than it is found that they hate fire and dragonglass (obsidian) - obsidian was used to fight off the others in the ancient times, as all ancient weapons daggers, arrowheads etc are made from obsidian.
cat was killed at the red wedding along with"king" robb and his wolfthe reanimated corpse of cat is kept alive by different magics than what the wights and others. her bloated waterlogged corpse is retrieved from the river by beric dondarrion who is leader of a outlaw band who was kept alive by weird magics, because he was gutted, hung and killed many times and was constantly being brought back to life. he gave his life to reanimate her so now shes a bloated waterlogged zombie who is a little more than slightly crazy
i probably should have spoiler blocked that whole thing but most of it wont happen for a nother season or 2