Interim UFC Featherweight champion Conor McGregor is currently preparing for his title unification fight against UFC Featherweight champion Jose Aldo at UFC 194. "Notorious" had an unlikely visitor at the Straight Blast Gym in Dublin, Ireland, per The Daily Mail.

That visitor was Icelandic strongman competitor Hafþór Júlíus Björnsson, better known as Gregor "The Mountain" Clegane from the popular television show "Game of Thrones" based on George R.R. Martin's "A Song of Ice and Fire" book series. The interim champ was courageous enough to spar with "The Mountain," and you can see the video below.

The 28-year-old MMA fighter was able to get some body punches to Björnsson that can't seem to catch the speedy Irishman. At one point in the video, the almost seven feet tall Icelandic dropped to his knees due to the body punches.

McGregor proceeded to give him a beating on the ground with punches and knee strikes. It all looked like that it was done for fun and McGregor was lucky enough not to get caught and got his skull crushed.

Björnsson stands at a towering six feet and nine inches and weighs 397 pounds. According to Iron Mind, the 26-year-old strongman was a former basketball prospect, who suffered a severe knee injury that cut his career short. He was discovered by Icelandic strongman Magnús Ver Magnússon in 2008 and started training him to become one.

“The Mountain” took part in the World’s Strongest Man competition and ranked sixth in 2011. He then climbed up to third place in 2012 and 2013 before finishing as runner-up last year to eventual winner Lithuanian Žydrūnas Savickas, per The Washington Post.

In his UFC Profile, McGregor is listed at five feet and nine inches and fights in the 145 pound division. He has career record of 18 wins and two losses with 16 wins coming by way of knockout and one by submission. "Notorious" has 12 first round finishes and currently has a 14-fight winning streak, six in the UFC.

He is also a former featherweight and lightweight champion for Ireland's Cage Warriors, and has a brown belt in Brazilian jiu jitsu. McGregor's teammate, Gunnar Nelson, also posted a photo of Björnsson's visit on his Instagram account.

 Absolute honor to have my Viking brother visit us training, a beast of a man!! @thorbjornsson #themountain #180kg

A photo posted by Gunnar Nelson (@gunninelson) on Oct 30, 2015 at 11:47am PDT