I've watched the scene from Suspiria several times now, and it's odd, because it's very similar to what I remember, and I think it's it, but it's different enough that I still have a little doubt. The eyes aren't actually red, but rather green, and they look cartoony. And there's parts of the scene that are different than what I remember, but then again, it was many years ago and I was young, and it's hard to dispute the similarities. If that is what I saw back then, I can definitely see how, between the hairy arms and long nails, I mistook the killer for a werewolf. Of course, then I should ask my parents what the heck they were thinking having something like that on the TV with me around
Thanks for the suggestions everyone, and if anyone comes up with any ideas on the off chance there really are two movies with scenes like this I'd still be interested to know.