It's always entertaining to see Hollywood heartthrobs undergo ugly transformations to fulfill an acting role, and Ewan McGregor is just the latest to do so with his appearance in the forthcoming third series of FX Network's 'Fargo' according to a recent promo clip.

Ewan McGregorEwan McGregor is unrecognisable in 'Fargo'

Ewan's usual glorious hairstyle is replaced by a massively receding greasy bob and it's clear that he's put on a bunch of weight around the middle. He also has a mustache and a rough chin of stubble, as well as a dated 70s/80s ensemble in the footage (despite the fact that it's meant to be set in 2010).

The clip features Ewan's character, Ray Stussy, leaving a diner with a scantily clad female friend immediately after spotting a cop making her way to a table. As they get into his car outside, the neon lights of the establishment flicker so that it reads 'DIE' instead of 'DINER'. It seems obvious that Ray's role in the story is a nefarious one.

Last year, the actor told Jimmy Kimmel that he had to 'load on a bit of weight' for his part in the series. '[I am] just eating, like, loads of food. Anything I want whenever I want', he explained. 'I have to be bigger than I am right now.'

His rather scary transformation reminds us of a few other times Hollywood's most handsome have forfeited their looks for a role. Johnny Depp was almost unrecognisable as James 'Whitey' Bulger in 'Black Mass', Tom Cruise couldn't have looked less sexy in 'Tropic Thunder', Christian Bale was skin and bone for 'The Machinist' and Tom Hardy was pretty terrifying in his 'Bronson' lead role.

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Season 3 of 'Fargo' arrives more than a year and a half after season 2 aired, and with an all new cast including Carrie Coon, Mary Elizabeth Winstead, David Thewlis and Jim Gaffigan. Ewan McGregor plays both Ray Stussy - an embittered parole officer - and his older brother Emmit Stussy who is the much more handsome and successful of the siblings, and the cause of much resentment building up within Ray.

'Fargo' returns to FX for season 3 on April 19th 2017.