I think it's a common one - I've certainly seen it several times before. This movie has a short clip of a black and white film where a woman is seen (who may have locked herself in a laundry room - details are hazy) backing away from a furry mass with a tail, a bit like a rat/brain combination. It wiggles, she screams, and the clip ends.
Any ideas? The clip isn't scary at all, by the way, and I think the "outer" movie's a comedy.
This clip appears in It Came From Hollywood, as part of a montage of scenes of women being attacked by mobile brains. That was, I suppose, a trope in low-budget mid-20th-century horror/sci fi films.
The specific movie depicted may be Fiend Without A Face.
This intelligence soon begins to multiply its numbers by claiming even more local victims. These creatures later become visible while continuing to feed on the higher levels of power now being generated at the airbase. Their mutated "bodies" are revealed to be the missing, now enlarged brains and connected spinal cords removed from their victims; the spinal cords have become very flexible and have sprouted feelers. These mutations allow the creatures to move quickly and even to leap; each brain has also developed a pair of small eyes on extended eye stalks.
The film climaxes with the visible creatures attacking an isolated house where most of the film's main characters have gathered to discuss the growing crisis. Having come armed, the defenders discover the creatures can be easily dispatched with well-aimed gun shots to their exposed brain-bodies.
Is it Terrorvision? http://www.imdb.com/title/tt0092074/
The characters watch several old black and white movies during the film. Its been a while since I saw it so I'm not sure if the scene you mentioned is definitely there but it could be worth a look.
