WATCH: UFC Star Conor McGregor Spars With 'The Mountain' From 'Game of Thrones'

UFC fighter Conor McGregor tangles with Hafthór Björnsson, known as 'The Mountain' on 'Game of Thrones.'

You don't often see a fight matchup with such a large size difference, and that's normally to protect the smaller guy. In this instance, the smaller guy is UFC star Conor McGregor, who stands 5-foot-9 and weights 145 pounds. His sparring opponent? The man they call "The Mountain" on HBO's hit series Game of Thrones, Hafthór Björnsson, who stands 6-foot-9 and weighs 419 pounds.

No matter how big you are, you have to be brave to fight someone called "Mountain." Most people would either run away or fake an injury.

So what happened? Did Björnsson just grab McGregor and squeeze him until he tapped?

To see the outcome, watch the entertaining video below:

Photo Credit: Getty Images // Thinkstock