Kit Harington, Samberg Join All-Star Cast of HBO's Sports Mockumentary

(Photo: YouTube screengrab)Kit Harington as Jon Snow in "Game of Thrones"

Kit Harington, who stars in HBO's "Game of Thrones," is set to join an all-star cast of another HBO production titled "7 Days in Hell."

The HBO Comedy Event will be a sports "mockumentary" following professional tennis players preparing for a seven-day match at Wimbledon. Harington will star opposite of "Brooklyn Nine Nine" star Andy Samberg, while Lena Dunham, Will Forte, Karen Gillan and Soledad O'Brien are also cast members, according to The Hollywood Reporter.

Harington, who is best known for his "Game of Thrones" role as Jon Snow, will portray Charles Lloyd Poole in "7 Days in Hell." The character is described as an Andy Murray-type prodigy and certified truck driver who will take on his fierce tennis rival, Aaron Williams (Samberg), at Wimbledon.

Also among the all-star cast is "Portlandia" star Fred Armisen, Michael Sheen, Mary Steenburgen, Howie Mendel, and June Squibb. Additional details about "7 Days in Hell" are not yet known, but more cast members are expected to join the mockumentary.

Harington's comedic role on "7 Days in Hell" is a far cry from his brooding character on "Game of Thrones." The 27-year-old Brit recently discussed Jon Snow as well as the future for the character on "GOT."

"There's a huge amount riding on him to be a leader, and I want him to become that leader," the actor explained to GQ magazine. "I guess for me, Jon Snow is a figure of hope within the whole thing- that he'll continue to be this good person, somehow the story will end well for everybody."

Harington also noted the notorious violence featured on "GOT," warning fans of the television series that the violence "doesn't stop" in future seasons.

"It's getting worse," Harington said. "There's some scenes this season, and there's parts of it that go even darker. The gruesome stuff- we've seen 'Saw,' we know that, you can do that 'til kingdom come. People can deal it. What I wonder is how people can deal with something going dark and dark and darker. Being unrelenting in how pessimistic things are. They really push it."