Such a creature would be damn near utterly unstoppable. A silver bullet kills a werewolf, but doesn’t do anything to a zombie or a vampire. A vampire is killed by a wooden stake in the heart. Now, even if you could get close enough to a werewolf to stake it, it won’t be bothered at all by a little “splinter”. Nor would a zombie. A regular bullet in the brain of a zombie would stop it, but of course it would do nothing more than annoy a vampire or a werewolf.

However (you might say) chopping off the head has proven quite effective against both zombies and vampires and it would probably work on a werewolf as well. Well, that is a possibility (after all I don’t claim to know everything on the subject), however; if you watch the movie “The Monster Squad“, there is a scene in which they stuff a stick of dynamite in the waistband of a werewolf. He gets blown into several pieces and at first seems to be a goner, but after a minute he reintegrates and just looks extra mad at the inconvenience.

Therefore, I think the only thing that could kill this Ultra-Monster is a silver-coated, wooden bullet in the brain (and the heart, for good measure). But who would have the necessary skills to make something like that?

Hey, I just thought of something that totally blew my own mind. What if King Kong was attacked by a werewolf, a vampire and a zombie…?