Well, this is embarrassing. An extra in the background of Teen Wolf accidentally had an "XYZ" moment... This was such an iconic moment that shows like Family Guy even parodied it. Was this on purpose? Did this extra know what they were doing? Or, was it a total accident that they will never live down?
Pirates of the Caribbean
This film series is obviously set hundreds of years ago, so naturally, everyone will be dressed in the garb of that time period. Funny enough, a production member (probably?) accidentally got in the background. This made for a very confusing frame of the film! We can only assume this was an accident since he is definitely not dressed for the right time period.