I knew Du were going to say Goku as soon as I saw your name. <.<
Anyways,that really depends. I mean personally I think all the magical creatures might have a chance but I can't be 100% sure. Besides,didn't Goku die several times already in his anime? (But he keeps getting revived with the dragon balls. What a waste,really. ._. )
well i am not a super DBZ fan... nor do i know a lot about the show... and there are MANY types of Vampire and Werewolfs... as shown in all the different "Beliefs" about them... i guess i'm gonna chalk this one up to... "Let the fight begin... and may the Best Creature WIN!"