Check it out ... the unnamed culprit is seen wearing dark coveralls and the signature mask of the murderous villain in the "Halloween" horror franchise ... best known for starring Jamie Lee Curtis.

In a video making the rounds online ... the masked rascal carries a fake knife while creeping up on cars stuck in a nightmare traffic jam north of Phoenix, Arizona.

Ryan Blauvelt, who encountered the trickster on Interstate 17 near Black Canyon City, shared footage from the scene on Facebook.

While Ryan encouraged anyone with information to tag the prankster, he made it clear he wasn't upset by the early Halloween fright ... applauding the person for making their wait "more fun."

Though the masked man was described as in "character" while moving from car to car in the prank ... there were no acts of violence, with the person looking for fist bumps instead of murders.

Nonetheless, not everyone was sold on the Michael Myers dupe's antics ... with some noting they would've had a "heart attack" if faced with this prank.