A cow-catcher is a zombie whose jaw has been removed by any means, for any reason. With its jaw removed, the zombie becomes much more harmless as it is unable to bite. However, none of the zombie's strength is removed, so it can still grip onto survivors and its blood is still contaminated. One reason to create a cow-catcher is to make it easier to navigate through a crowd of zombies. This only works, however, if the survivor(s) are already covered in zombie guts.