James Cameron met fire with fire after storming through a crowd of autograph-seekers that he had no intention of satisfying ... fleeing the scene with a message from a little birdy.
The famed director was leaving the WGA building in Beverly Hills Saturday, this after they held a special screening of his new film ... 'Avatar: The Way of Water,' which hit theaters this weekend. On the way out, there was a crowd for JC -- but he was in no mood to please.
Rather than stop and sign stuff that these folks were desperately hoping he would ... Jim just powered his way through without giving anyone the time of day, or the power of ink.
When it became clear he wasn't autographing squat ... the fans turned on him, jeering him as he got into his waiting SUV -- and even condemning his movie ... shouting, "F*** Avatar!" James had something for them almost immediately -- flipping them off out of his window.
Unclear what had him so sour ... but it's a pretty hilarious interaction nonetheless.
Of course, the weekend box office numbers for James' new movie aren't as great as some hoped -- which could affect future sequels he had planned. If it turns out that 'Way of Water' isn't the box office boom Disney wants, we suppose that's reason enough to be a Grinch.