The Oxford comma varies by the style you're using and what you're doing. Some times you will have to use it, sometimes the style guide lines prohibit it. But as long as your sentence is clear you'll be alright without it (the fast, vicious and strong man-bat vs the strippers, JFK and Stalin). It can be quite a pain, and unless style guides say otherwise you're better off using it to maintain consistency when making sure your sentences have clarity. The fast, vicious and strong man-bat certainly works, and there is nothing grammatically incorrect about it, but when you add the strippers, JKF and Stalin, it's confusing without so it should be used, which mandates for consistencies sake (assuming it would be the same document) that you have a fast, vicious, and strong man-bat and the strippers, JFK, and Stalin.