The strongest man on the planet and the baddest dude on "Game Of Thrones" says there's no way in hell he could fight Deontay Wilder or Tyson Fury ... 'cause The Mountain says they'd END him!
We got Hafthor Julius Bjornsson -- aka Thor, the 2018 World's Strongest Man -- out at LAX when he told us if he fought the heavyweights ... it'd be lights out for him.
"Right now they are the best, and there's no way a guy like myself that doesn't train in the sport can just go in there and beat them."
The tale of the tape is pretty interesting -- The Mountain comes in at 6 feet 9 and over 400 pounds. Wilder tips the scales at 6'7", 212 -- and Fury comes in at 6'9", 257.
Despite the massive weight difference ... Hafthor ain't even giving himself a chance to last 1 punch -- let alone 1 round.
"If I were to be punched by a guy like Fury or those guys in the face, I would probably get knocked out the first hit."
Remember, Bjornsson did spar with Conor McGregor -- and dominated the Irishman -- but it's clear he knows his limits.