Unfortunately for film-makers, they can't always pay professional actors to fill their scenes and convincingly just act like human beings without falling over or doing something to mess up the scene entirely. So even the most impressively cast films have to be filled out with normal folk like me and you, told to walk back and forward, not look at the camera and just generally not to draw any attention whatsoever, unless instructed to do so.
Inevitably, this goes wrong quite often, and though the majority of Extras mistakes will never see the light of day, some are infamously left in the final films, either through editing negligence, or the financial constraints of reshooting or removing them. And what follows here is a celebration of nine of those instances, when Extras have - in one way or another - completely ruined the scene they were asked to take part in. So read on, and point and laugh if you like - it's probably the right thing to do.
Disclaimer: Before anyone says it in the comments thread, I already realise that an Extra isn't really an Extra if he has a line of dialogue to deliver, but in my world, if someone has less than a minute on screen, the idea of them being called a Guest star is something of a stretch, so they're getting lumped in here as well.