One Musical Bunny
Simply because it won't leave me alone; a movie-verse story set to the tune of this: http://www.youtube.com/watch?v=ny7NZPfl0l4&feature=related
Not necessarily following the full story of Mordred, but kind of like Megatron having gotten a hold of a sparkling/youngling Starscream, could be his creation or not, and raising him to hate Optimus and want to kill him. I'm not sure I'm explaining it very well...