Good Omens co-author and producer Neil Gaiman explains that David Tennant was his first choice for Crowley, but the studio preferred Johnny Depp.
David Tennant's performance as the demon Crowley in Good Omens has been widely celebrated, but he wasn't the first actor that Amazon Prime Video considered for the role. In fact, at one point the studio wanted to cast Johnny Depp.
Neil Gaiman, co-author of the book Good Omens and executive producer on the show, answered a question from a fan on Tumblr who wanted to know which part took the longest to cast. "David Tennant," Gaiman replied. "I told Amazon I wanted him to play Crowley early in 2017. They did not see it. They thought he was too much like [Aziraphale actor] Michael Sheen, they wanted a movie star, particularly Johnny Depp. I didn't."
Gaiman went on to explain how his favored actor eventually became the Crowley known to fans of the show today. "The process of not-casting David went on for months," he recalled. "Finally David was one day away from agreeing to make someone else's movie, and I phoned Amazon and told them that if they didn't agree to cast David we didn't have a show as I didn't have another choice, and they had to trust me. And they sighed and said 'Well, if you're that passionate about casting David, okay.'"
Before Good Omens, Tennant was known for several major TV roles, including his run as the Tenth Doctor on Doctor Who. When he appeared as Crowley, audiences quickly fell for his swaggering portrayal of the demon and his onscreen chemistry with Sheen's fastidious angel character.
The popularity of the series earned it a surprise second season with Sheen and Tennant returning, although the first had already covered the story from the novel by Gaiman and Terry Pratchett. "The new season will explore storylines that go beyond the original source material to illuminate the uncanny friendship between Aziraphale, a fussy angel and rare book dealer, and the fast-living demon Crowley," Prime Video said in a statement.
Gaiman made a wry reference to the success of Tennant and Good Omens in his Tumblr post, saying, "Later, the people at Amazon admitted that I might have had a point. These days they are very happy that I stuck to my guns and that they were willing to humour me."