The Barbarians' dressing room wasn't just full of hype after the side claimed an unlikely 38-35 win over the Pumas on Sunday morning (NZT).
A video posted by the club, which has since gone viral on social media, has revealed the extraordinary way the iconic team prepared before taking to the field against Argentina at Twickenham.
Rather than forming a team huddle or reinforcing game plans, the Barbarians broke out into passionate song just minutes before kick-off, singing 'He'll be coming round the mountain Malcolm Marx' led by South African lock Lood de Jager.
The team grew increasingly louder each time the verse repeated with many of the player's fist pumping and jumping up around each other.
The video has since been shared on Twitter with many fans applauding the team's amusing approach.