It sure seems so. There was some surprise here and there on the web when Momoa revealed he had written a treatment for the Conan sequel, which he hoped they would use if to goes ahead. And there was certainly surprise and amusement in the fan community when Momoa made it clear on several occasions that he’d love to return to Game of Thrones, suggesting Drogo could have a twin brother or that magic might somehow be involved.
But did anyone realize that he actually wrote scenes featuring a returned Drogo, which he’s apparently presented to executive producers Benioff and Weiss? Because, according to his interview with NY Magazine’s Vulture site, that’s exactly what he did. Here’s the relevant quote:
I wrote some scenes and they might try to use them. George [R.R. Martin] can only write so much. Something could happen. Drogo could have a twin. You never know.
Got to love his enthusiasm for the show. Speaking of that, he was on Conan O’Brien last night. Here’s an embed of his appearance, where Game of Thrones is mentioned, although much of it is about his soon-in-theaters Conan 3D: