Jason Momoa

Jason Momoa can't wait for fans to hear what Khal Drogo will say next, especially following last week's shocking Game of Thrones conclusion, in which he gave his brother-in-law Viserys a "golden crown" of molten death.

In Sunday's episode, "You Win or You Die" (airing 9/8c on HBO), an enraged Drogo delivers a lengthy speech after his wife Daenerys (Emilia Clarke) is threatened. It not only reveals his martial side, but also shows that the previously quiet leader of the nomadic Dothraki can string together more than a couple words.

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"I'm dying for my friends to see me make the speech," Momoa tells TVGuide.com. "My friends who watch the show all just keep saying, 'Dude, you don't say anything. You're just naked!' And I'm like, 'I swear to God, I say stuff!' Drogo makes this beautiful war speech and dedicates it to his wife. He's going to f--- some s--- up."

Up until now, the khal has been taking more of the imposing, silent partner role in the marriage -- having wordless sex in a tent and occasionally grunting while sitting next to the campfire. "I base him off of a silverback or a lion," Momoa says. "It was my first time ever to play a king kind of role. You wanted to make him stone-faced, sort of impenetrable. Being arrogant was fun, you know? But when I go back home after work, my wife would slap me back down. She's like, 'You have to take the garbage out.'"

Although Khal Drogo isn't relegated to garbage duty in his marriage, Daenerys does have an influence on him. "He's a super-stoic character but when he falls in love with this beauty, you slowly start to find his heartstrings," Momoa says. "He warms up to someone, which is something he's never done before. Drogo is starting to open up."

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Although playing such a role and dealing with its rigorous language requirements were new to Momoa, physically at least, he seemed born to play Drogo. In fact, he had just finished shooting Conan the Barbarian, the remake of the classic Arnold Schwarzenegger film in which Momoa plays the titular warrior. When he went on to shoot Game of Thrones in Belfast, Ireland, he found the muscle mass acquired to play Conan helpful to embody Drogo.

"It was great coming off of Conan because it was really hard training," says the actor. "For Conan I had to eat boiled chicken breast and work out all the time and basically eat like a bird every two hours and stay ripped. But I'm bigger in Game of Thrones. Drogo is like 7-feet tall in the book. So after training really hard for five months, when I got to Ireland, I had Guinness, pizza, spaghetti and whatever I wanted. You put all that fat on top of the muscle and you look heavyweight. I gained so much weight. Later, we had to go back for a photo shoot and I was 30 pounds lighter. I didn't even fit into my wardrobe, the minimal wardrobe that I had."

Even though Drogo doesn't wear much clothing, the actor found that the hair and makeup helped him get into character. Among the Dothraki, the length of one's braid indicates their success in battle. Drogo remains undefeated, which is why he's the khal. Another touch added to the character -- that wasn't described in George R.R. Martin's A Song of Ice and Fire novels on which Game of Thrones is based -- is his heavy eyeliner.

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"It was interesting to find a wig that wasn't too heavy but was long enough," Momoa reveals. "They clipped it on in the back and wove it in. The eyeliner thing came about just because in doing the research, you learn the nomads travel across plains and deserts. They always wear the eyeliner so it reflects the sun. That's why I designed it for that. I thought it would be a good character trait."

Luckily, the actor didn't have to contend with any makeup malfunctions, namely runny eyeliner. Quite the opposite in fact. "No, it didn't run," he says. "I had so much on I guess it completely caked everywhere."

In fact, Momoa found he had difficulty removing the eyeliner at the end of the night, which created some difficulties when walking around Belfast.

"The show wanted me to keep my own mustache so I had this horrible '70s porn mustache on," he says. "So I was walking around Belfast -- I'm dark-skinned and 6-foot-5, with eyeliner and a really disgusting mustache -- and I'd have to apologize to people and say, 'Listen, I'm sorry. I'm working here. No, not as a transvestite, but I'm working on a show.'"

Game of Thrones airs Sundays at 9/8c on HBO.