The 'Game of Thrones' star also opens up about his new clean-shaven appearance and "big moments" in the show's final season.
In 2017, the actor made headlines for scaring the hell out of now-wife Rose Leslie by placing a severed head from the show's props department in their refrigerator. This year, he still managed to freak her out, but he suffered a few consequences as well.
"I started strong," Harington told Seth Meyers on Monday night, before admitting, "The amount of props at my disposal has diminished."
He went on to explain what he pulled this year, prefacing his story by calling it "the most first world April Fools'" prank ever.
"She has a favorite almond milk, she won't drink any other almond milk, so I just wrote an article about how this company that makes her favorite almond milk was going under because of Brexit," he explained. "Now this backfired, because she immediately rang my PA and got her to bulk order this almond milk with my credit card. So I ended up spending 150 quid on almond milk."
His Meyers appearance comes after Kit hosted "Saturday Night Live" over the weekend, a move that forced him to switch up his look a bit.
When he hit the "SNL" stage, he shocked everyone by rocking a totally clean-shaven face, something he said he had to do to play Michael Jackson and Winston Churchill during the episode. Even he admitted it's a different look for him.
"So they shaved me and it's the first time I've had a reason to shave in a long time," he told Seth. "I did it and I feel like I look like a tired child."
Harington went on to say there are "definite big moments" in the final season of his HBO show -- not really a surprise, but we'll take anything at this point.
And while talking about his stint as a dead body on the show, Kit also teased a possible career for him after "Thrones" airs.
"I loved that couple of days. They warmed the room, I was on a table asleep. I literally fell asleep in those scenes," he said. "That was some of my best work. I hadn't had a compliment by some of the crew at all for my work, they were like, 'You do a really good dead body.' There's a future on 'CSI' for me."
The final season of "Game of Thrones" kicks off this Sunday on HBO.