WATCH: 'Game of Thrones' Season 4's Gregor 'The Mountain' Clegane Actor Dresses Up As Hulk For 3-Year-Old's Birthday [VIDEO] Will Marvel Take Notice?

You may know world lifting champion Hafþór Júlíus Björnsson as Gregor "The Mountain That Rides" Clegane from Game of Thrones season four, but just last month he portrayed a more notable character: Hulk! Getting his body painted the appropriate green, Björnsson get into character for a three-year-old boy's birthday party. Check out what happened when the birthday boy saw his hero Hulk show up to the party!

Hafthor (as the massive muscle man will be referred to from now on for typing reasons) might have been incredibly menacing and terrifying in this last episode of Game of Thrones, but the strongest man in Iceland showed his jolly side in order to make a three-year-old's birthday extra special.

Unfortunately the HBO star looked too convincing for the birthday boy, making him break out crying at the giant man painted green.

Either way, the party seemed to only have that one problem and Hafthor posed for photos with the children, turning the party into a great time!

Check out the video of the party as well as Hafthor's body painting that took place before the bash:

If you liked that video, we have another treat for you. Here is some footage of Hafthor deadlifting 994 pounds, retaining his title of the second strongest man in the world.

Gawker reports:

Björnsson, the second-strongest man alive, stands 6'9" tall and can bench press 500 pounds, squat 770 pounds and "raw" deadlift 925 pounds. In this video from the 2014 Arnold Strongman Classic, he handles an insane 994 pounds in the hummer-tire deadlift.

Watch the video here: