See 'Game of Thrones' Star Jack Gleeson as a Little Kid in 'Batman Begins' [Video]

Kelly Woo
·Writer, Yahoo Entertainment

Before he was a king, he was just a kid who looked up to Batman.

Ever since "Game of Thrones" premiered in 2011, Jack Gleeson has earned fame and acclaim as the ruthlessly evil, sadistic King Joffrey. The 20-year-old actor's scary-good performance has made Joffrey one of TV's greatest love-to-hate villains.

But before he was beheading innocent men and torturing women on the HBO drama, a very young Gleeson appeared in the 2005 blockbuster "Batman Begins," in one of his earliest onscreen roles. If you don't remember, he was a poor kid from the Narrows who was saved by Batman.

Watch his brief appearances:

The cameo has inspired quite a few memes mashing up Gleeson's sweet, innocent kid in "Batman Begins" with the bratty, spoiled, mean Joffrey:

That's not the only surprising fact about this accomplished young actor. Check out five things to know about Gleeson:

1. He almost didn't play Joffrey.

Gleeson was actually supposed to be the body double for an actor the producers originally had in mind for the role. Instead, they asked him to audition, and a king was born.

"It was like he flipped a switch and he became the most despicable teenager on the planet," co-creator David Benioff explained. "He's genuinely one of the sweetest guys I've ever met."

2. Contrary to popular belief, he doesn't get bullied by Joffrey haters.

While his co-star Sophie Turner (Sansa) worries that Gleeson will get slapped by someone on the street, he said that fans treat him well.

"Nobody's ever said a mean thing to me," he told Entertainment Weekly. "Instead people say, 'Are you OK? I hear you get bullied on the street.' And I say, 'No! Everybody's been really nice.'"

3. Sansa might hate Joffrey, but Sophie Turner is Gleeson's biggest fan.

On screen, Gleeson and Turner's scenes are filled with tension, loathing, and cruelty. Offscreen, the two friends enjoy goofing around. "He was rapping about Winnie the Pooh," she told EW. "His rap was called 'Got Monies and Honies.'"

[Related: Sophie Turner and Natalie Dormer on Their Budding Friendship On and Off Screen]

She added, "I don't think he gets enough credit for what he does. Jack is such an insane actor and he's able to change like that."

4. He's a supersmart scholar.

Gleeson, who attended Trinity College in Dublin, hopes to return to academia someday. "After 'Game of Thrones' I'd be happy to do some amateur plays but I don't think I want to do any more professional acting," he told the Irish Independent.

"I'd like to be an academic, a philosophy lecturer if possible. I'd do a masters in ancient Hebrew maybe, and a PhD hopefully, if I get in."

5. He's a puppeteer!

Gleeson co-founded the Collapsing Horse Theatre Company with fellow Trinity College students, and the troupe recently put on a musical puppet show called "Monster/Clock."

Watch Gleeson in puppeteering action:

"Game of Thrones" airs Sundays at 9 PM on HBO.