Tom Hiddleston has no problem facing off against a gargantuan gorilla, but apparently Brie Larson in a spa mask spooks him.

The Kong: Skull Island co-stars flew home from promoting their adventure epic in Tokyo on Wednesday, and Larson took to Instagram to share her thanks with Japan Airlines for their luxurious amenities -- including a relaxing face mask.

WATCH: Brie Larson Bucks the 'Damsel in Distress' Trope for 'Kong: Skull Island'

"Bye bye Japan. I love you. And thank you @japanairlines_jal for the in flight spa day," Larson wrote in the caption. "It made me so happy and also scared Tom."

To Hiddleston's credit, that mask is the stuff of nightmares. It looks like something a serial killer would wear in a high-brow French horror movie.

While the 36-year-old actor might have had gotten scared on the way home, he seemed to have nothing but a great time while in Tokyo, where he hung out with his other co-star, Samuel L. Jackson.

WATCH: Tom Hiddleston and Brie Larson Light Up the Monster-Sized 'Kong: Skull Island' Premiere

He and Jackson stopped to snap a selfie together to commemorate the trip, which Hiddleston posted to Instagram, writing, "We had such fun in Tokyo introducing #kongskullisland. My first time in Japan. Thank you to all the fans who came out to say hello!"

For more on the latest installment in the King Kong mythos, which opened last Friday, check out the video below.