A post in the Challenge thread got me thinking about this, plus I watched Deadline last night, which qualifies...

...so what are some horror films that feature other, unknown/fabricated films or films made specifically as part of the plot device for the film in which they appear. E.G. in Deadline one of the films that is currently being produced is not an actual film that I'm aware of, and in the film Found there is a fabricated (but then subsquently released) film "Headless".

...any others? And if this post doesnt make sense it's because it's 5:43am and I haven't had coffee yet