New York, New York - The upcoming movie A Different Man is filming in New York, but who is under the mask of its striking main character?

This film is certainly holding true to its namesake, A Different Man.

For his latest turn, Marvel star Sebastian Stan appears under such heavy makeup that it's almost impossible to guess who he is.

In a new Instagram post, the 39-year-old actor shared a photo of himself on set in his new role - but his face is covered in prosthetics.

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"Incredible work," the actor wrote of his transformation.

Behind the magic is mask aficionado Mike Marino, who also recently transformed actor Colin Farrell into the Penguin for The Batman (2022) and has worked on numerous blockbusters such as Joker (2019) and The Irishman (2019).

But exactly why has Sebastian Stan made such an extreme transformation?

In the psychological thriller A Different Man, Stan plays a man who suffers from neurofibromatosis, which causes his face to be covered with blemishes and tumors. The man begins to have his face surgically restored, and becomes obsessed with an actor who plays him in a play based on his own life.

A24 Films is the production company behind the new movie. The young studio was behind hit films such as Hereditary (2018) and Everything Everywhere All at Once (2022).

The company coincidentally has a new movie dropping next month – The Whale – in which another actor, Brendan Fraser, also makes a huge physical transformation to play its main character.

Sebastian Stan's fans, meanwhile, are thrilled with his shocking transformation, his latest since his most recent transformation into rocker Tommy Lee for the hit Hulu miniseries Pam & Tommy.

"The makeup team has outdone themselves. Incredible," one fan wrote on Instagram of his new role.

"Sebastian, is that really you?" another commented.

"This movie is going to be amazing, I can feel it already," another user wrote.

A Different Man's release date has not been announced, but it is expected to arrive in the middle of next year.