What do Devon Lariat and Hafthor Bjornsson have in common? They're both ridiculously, incredibly strong. Lariat is a world champion arm-wrestler (who knew there was one?) and Bjornsson has inspired many-a-nightmare starring as The Mountain on HBO's Game Of Thrones. So who will win? Watch and find out for yourself. If you don't watch it to see the outcome, watch to see how strained their faces look.