VIDEO: See how Johnny Depp became Whitey Bulger

Johnny Depp has played a lot of strange characters over the years, particularly since he first put on the Captain Jack Sparrow hat back in 2003. And now he's about to add another enduring character to that mix.

This difference this time is that Depp is embodying a real person - the notorious criminal Whitey Bulger for the film Black Mass. It's about Bulger's dirty dealings with the FBI as brought to the screen by director Scott Cooper. We've seen photos and video of Depp in costume and he looks nothing like his normal self, and also honestly not much like the actual Bulger. But it seems this process was even more pronounced on set, according to this behind the scenes featurette.

We would have liked to have heard at least a few words from Depp himself but maybe that would have spoiled the effect set up by the startling transformation. The film recently had its world premiere at the Venice film festival and early reviews are saying that the actor gives an amazing performance that might be the best of his career. And after more than a decade of wearing funny hats and spouting English accents, that's very good news indeed.

Black Mass is in cinemas in the States in September and arrives across the pond on the 27th of November 2015.