Answer: Alan Rickman

Of all the members of the large and accomplished Harry Potter film cast, only one person had the inside scoop and an idea of how the story was to unfold. Alan Rickman’s role as Severus Snape was so pivotal to the development of the story (and such a dynamic role) that Harry Potter author J. K. Rowling shared a ‘left of field’ piece of information with him.

Before new Harry Potter books were converted into screenplays, Rickman was able to use information from them in combination with the vital piece of information she originally shared with him to shape Snape’s character all throughout the series.

Although Snape’s character was dynamic and shifting throughout the entire series (of both books and films), there was one particular constant: his wardrobe. By Alan Rickman’s insistence, Snape wore the exact same black frock for every single film.