Nikolaj Coster-Waldau
"Game of Thrones" actor Nikolaj Coster-Waldau, pictured at the 21st annual Screen Actors Guild Awards in January 2015, recently pulled an elaborate prank on fans. Reuters

“Game of Thrones” is typically pretty good to its fans, but sometimes the cast can’t help but stir up a little trouble. Most recently, Nikolaj Coster-Waldau pranked a good number of book fans with a fake spoiler.

In a recent interview, the actor, who plays Jaime Lannister, just couldn’t resist an opportunity to mess with die-hard readers of George R.R. Martin’s popular “Song of Ice and Fire” book series. With so many "GoT" fans clamoring for the latest spoilers and inside information, the actor had a little fun in a promotional video with HBO Nordic. A fan site for the actor captured the moment just before the camera stopped rolling on him when he grabbed a duck stuffed animal and held it by the neck up to the camera.

“Just wanted to introduce this duck,” he said with a coy grin. “It’s a spoiler for the book readers. I won’t give anything away… Think about it.”

From there, Vanity Fair reports, fans were off to the races trying to figure out what exactly the actor was trying to tease. While many thought that he was alluding to the introduction of a very mysterious, and possibly very vital, character from the book series, Coster-Waldau went on “Conan” this week to reveal that the entire teaser was just a ruse for his own amusement.

In the below video, he tells host Conan O’Brien that he simply saw the duck in the hotel room they were filming in and had the idea for the prank right there on the spot.

“It’s completely random. You could pick up a carrot and go, ‘Look for this!’ and they’ll go, ‘Ah! I know what that means!’” the host joked. “That’s so mean!”

While Coster-Waldau felt a little bad for messing with fans who adore him, they should all know better than to trust a Lannister. Prior to the Season 4 premiere, his on-screen sister Lena Headey posted a photo to her Instagram account of a collection of rocks arranged in a heart. Many book readers took this as confirmation that the character Lady Stoneheart from the books would appear in the season. Imagine their surprise when that didn’t happen and Headey went on Jimmy Kimmel to reveal that the photo was just a product of a drunken evening in Palm Springs.

Were you fooled by the now infamous duck teaser? Comment your spoiler-free thoughts below or tweet them to @TylerMcCarthy.