There's a change on Syfy's upcoming series Happy!

Patton Oswalt has replaced Saturday Night Live's Bobby Moynihan in the upcoming adaptation of Grant Morrison and Darick Robertson's Image Comics graphic novel of the same name, producers announced Saturday at Comic-Con.

Happy! centers on Nick Sax (Law & Order: SVU's Christopher Meloni) — an intoxicated, corrupt ex-cop turned hit man — who is adrift in a world of casual murder, soulless sex and betrayal. After a hit gone wrong, his inebriated life is forever changed by a tiny, relentlessly positive, imaginary blue winged horse named Happy (voiced by Oswalt).

"We asked him if he wanted to do it, and he was like, 'Fuck yeah,'" exec producer Brian Taylor told the crowd about Oswalt's involvement. "If you know Pat, this is right up his alley."

Moynihan parted ways with the project due to his increasingly busy schedule. The news comes as the comedian prepares to headline his first network series, CBS' upcoming Boyhood-like single-camera comedy Me, Myself & I. Moynihan exited Saturday Night Live in May after nine seasons in order to star in the CBS entry, which will film in Los Angeles.

Oswalt is also starring in a first-year broadcast comedy: the single-camera series A.P. Bio, which will air on Syfy sister network NBC and hails from Universal Television, the network counterpart to Universal Cable Productions, which is producing Happy!

When discussing the unique challenge of starring opposite a cartoon character, Meloni praised the experience. "It's fantastic. It's awesome. They're never late to set. They always know their lines," he said. "It's really kind of nice because you get to control the scene. I will say it's a luxury."

Taylor (Crank) co-wrote the pilot teleplay with Morrison and directed the pilot. The two exec produce with Neal Moritz, Pavun Shetty and Toby Jaffe of Original Film (The Fast and the Furious franchise), as well as Meloni and showrunner Patrick Macmanus.

When speaking about adapting the beloved property, Macmanus promised fans that the book would serve as the "spine" of the series. "The major touchstones are all in there," he said. "Hopefully you all feel like we expanded on it in an elegant way."

The adaptation marks Morrison's first foray into television. "It's like building the Sistine Chapel," he said of working on the series.

Morrison said the move to TV was a natural fit given the ability to tell long-form stories similar to comics. "We're used to writing in that mode," Morrison said. "I just felt it was the natural progression. I love movies, but trying to condense a decent comic book story into a movie can be quite difficult."

Added Taylor: "TV has become the Wild West now."

Looking ahead, Morrison said, "We know where we're going with this," in reference to potential future seasons of the series. "With any luck, Happy! will outlast the Trump presidency," Taylor half-joked.

While Syfy might seem like a surprising home for the series given the dark source material, the exec producers praised the cable channel for the creative freedom it offered during the production process. "It was a big concern for me. It was like, 'What are we getting into here?'" Taylor said. "Every step of the way, these guys at Syfy have been like, 'Go, go, go.'"

"Honestly, I think there's a new kind of show that you're going to start seeing on Syfy," he continued. "And hopefully this is one of those shows."

Teased Morrison with a laugh, "Just wait 'til you see Happy! on coke."

There is no premiere date yet for Happy!