Kit Harington at HBO's "Game of Thrones" final season premiere in New York. Picture: AP
Former "Game of Thrones" star Kit Harington's Black Knight role in "The Eternals" could grow into something more for the Marvel Cinematic Universe.

The 32-year-old actor will reunite with his former "Game of Thrones" co-star Richard Madden for the upcoming Marvel Cinematic Universe project when he becomes the first person to play Dane Whitman and his alter ego the Black Knight.

Teasing future plans, Marvel boss Kevin Feige told "Good Morning America": "He's a really amazing actor, and this part came up in 'The Eternals' film that we're doing.

"We were so happy when he agreed to join, and it is a part that could perhaps grow into something else in the future."

Harington and Madden previously starred together in the HBO fantasy epic - playing Jon Snow and Robb Stark respectively - and it will be the first time they've reunited on a major project since the latter's on-screen death during season three's infamous Red Wedding.

While details on the character's introduction into the MCU are scarce, the Black Knight was created by Roy Thomas and John Buscema, and first introduced to comic book fans back in the 1967.

Whitman takes on the alter ego because it is his family legacy, with ancestor Sir Percy of Scandia first taking the title during King Arthur's rule.

Dane hopes to redeem the name when he takes over the mantle from his late uncle Nathan Garrett, who used the mask for villainous means "The Eternals" will also star the likes of Gemma Chan, Angelina Jolie, Salma Hayek, Kumail Nanjiani and Barry Keoghan.

The film is set to go into production later this year, with a planned release in November 2020.