Black cats sure get a bum rap on screen -- always cast as the bad guys (or at least their familiars). This is not just a Western prejudice. For example, spooky black cats feature quite prominently in the Japanese horror hit JU-ON: THE GRUDGE, as in this scene wherein social worker Rika awakens to find some uninvited feline guests sharing her bed...
The cats appear to be multiples of the pet owned by the film's little ghost boy, Toshio, when he was alive. The shot works exceedingly well in theatres, where it flashes by so fast that you have time only to be overwhelmed by the creepy impression it leaves. On DVD, it is slightly less effective, because the Pause and Rewind buttons allow you to determine that many of the "cats" are actually statues (although since they're supposed to be ghost cats, one could charitably assume that standing perfectly frozen like a statue is just one of the ways they manifest themselves).
In Japan, there is a long tradition of "cat-ghost-vampires" -- i.e., dead people who come back in the form of cats to wreck vengeance on the living (and drink their blood). Perhaps many Western viewers don't realize it, but this has a lot to do with the presentation of Toshio in the JU-ON film (and their American remake, THE GRUDGE).
Toshio's pet cat was killed at the same time as he was. In death, Toshio is frequently seen in the company of the intimidating black cat; even more disturbing, he displays feline tendancies himself, occasionally emitting a cat-like yowl to the camera. Apparently, his spirit and that of the cat were in some way fused during their violent death -- a concept that is not explained in the films, because the idea of a "cat-ghost" is more or less taken for granted in Japan.