Mad Men star Jon Hamm will play the archangel Gabriel on Good Omens, Amazon and BBC's adaptation of the acclaimed 1990 novel by Terry Pratchett and Neil Gaiman.

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Good Omens is a comedic take of the coming of the apocalypse. It centers on the angel Aziraphale and the demon Crowley, who attempt to short-circuit the End Times, and the Antichrist who, because of a mixup at the hospital, is a seemingly normal boy raised by English parents.

Although Gabriel's role in the novel is relatively limited, Variety reports it has been expanded for the six-episode series.

“He is everything that Aziraphale isn’t,” Gaiman, who wrote the series and serves as showrunner, said in a statement. “He’s tall, good-looking, charismatic and impeccably dressed. We were fortunate that Jon Hamm was available, given that he is already all of these things without even having to act.”

He joins a cast that so far includes David Tennant as the demon Crowley, Michael Sheen as Aziraphale, Jack Whitehall as wage clerk turned witch-hunter Newton Pulsifer, Michael McKean as witch-finder Sgt. Shadwell, and Miranda Richardson as psychic medium Madame Tracy.

Terry Gilliam had hoped to adapt Good Omens for the big screen as far back as 2002, and in 2011 it was announced Terry Jones and Terry Jones would instead produce a television version. Of course, neither of those materialized. BBC Radio 4 did at last adapt the novel in 2014, with Gaiman and Pratchett appearing in cameos.