MrBeast , the YouTube superstar known for his challenge videos, has a new trial on his hands: negotiating a union contract with IATSE. The YouTuber’s Amazon Prime Video competition show Beast Games has voluntarily recognized an IATSE union and is negotiating a labor contract, The Hollywood Reporter has learned. Negotiations are taking place after a group of crew members on the set of the show’s third season began organizing with the crew union. Filming is primarily taking place in the hometown of Mr Beast, whose real name is Jimmy Donaldson: Greenville, North Carolina. Beast Games , a spectacle of over-the-top competition, offers 1,000 contestants the chance to win a $5 million prize with other high-value prizes being doled out in the process. THR has reached out to MrBeast and Prime Video for comment.…