​From Wikipedia, the free encyclopedia.   William Davies (sometimes credited William Davis or Will Davies) is an English screenwriter and film producer. He has written and co-written a number of Hollywood blockbusters including the 1988 Twins, Johnny English, Alien Autopsy, Flushed Away, and most recently, How to Train Your Dragon in 2010. Description above from the Wikipedia article William Davies (screenwriter), licensed under CC-BY-SA, full list of contributors on Wikipedia.