Watch Joe Naufahu get pranked by Emilia Clarke on Game of Thrones

Joe Naufahu's character on Game of Thrones suffered a fiery demise this week - but off camera things got just as sticky for him.

The Kiwi actor is seen being pranked by his co-star Emilia Clarke in new footage posted on Vulture.

The video shows Naufahu being smeared in caramel fudge while he sleeps, with Clarke stifling giggles as she spreads it over his hands and face.

"I had my dessert sitting on the table, and she decided to smear the dessert on me," Naufahu told Vulture.

"She put caramel fudge all over my fingers, all over my costume, and she was about to feed it to me, but I woke up. I woke up with a spoon in my mouth."

He said the pranking occurred during cooling down time for the actors while filming this week's fiery episode, which saw Naufahu's character Khal Moro killed by Clarke's Daenerys when she sealed him inside a blazing tent.

It wasn't the only time he was pranked. Naufahu also said Clarke would also write Dothraki words on his body while he slept.

"A lot of it was, 'Qoy Qoyi,' which means 'blood of my blood' ... maybe she was delirious from all the propane on set," he said.

But in an interview with the Herald, he said he got his own back, sneaking Tongan and Samoan words into Dothraki - a made-up language used on the show - during rehearsals.

"It sounded quite similar to Samoan and Tongan so I'd slip words in and they'd never know. I was a bit scared to do it in the takes, but I'd add a Samoan word or Tongan word here or there into rehearsals. Emilia caught wind of it and she started throwing her own made up words in there to throw me," he said.