Arnold Schwarzenegger Transforms Into Santa on 'The Man with the Bag' Set

Arnold Schwarzenegger was rocking very merry festive vibes -- and sleighing it on the set of his new movie, "The Man with the Bag."

The movie legend was spotted in full holiday mode -- wearing a Christmas jumper, snow-white hair and beard, strolling to his NYC trailer like the jolly old St. Nick he’s playing in the movie.

Arnold was practically incognito ... he could’ve been any random guy strolling the streets of NYC. If not for the crew and cameras, you'd think he was just another holiday shopper on a casual walk!

Arnold’s teaming up with Alan Ritchson in the movie, which centers on Santa’s magic bag getting swiped, forcing him to turn to his naughty list’s top thief to save Christmas.

This festive flick is shaping up to be a ho-ho-ho holiday hit! And it’s not Arnold’s first time in the Christmas movie game -- he’s been decking the halls since "Jingle All the Way" back in 1996 ... an Xmas classic!

In fact, Arnold’s been the Christmas King since his directorial debut in '92's "Christmas in Connecticut." Looks like he's got a real knack for holiday cheer!