You can open the creature.kwd file with a Hex editor. But only the animations can be corrected there... As far as I know.
In general, the behavior of creatures are saved in the global values of each individual map such as AlcatrazGlobals.kld or CavernsGlobals.kld. So to change their behavior you need to re-save each levels or return all the original maps, if they were changed in the patch.