Here is one of my favorite, if somewhat less talked, about spooky cartoons, 'Pink Plasma' (1975). The cartoon's gags are a bit familiar, but that's probably due to DePatie-Freleng Enterprises being largely staffed by former WB animators. (The Pink Panther's conflict with the vampire bares a lot of resemblance to the Bugs Bunny short, 'Transylvania 6-5000' made 12 years earlier.)
At any rate, 'Pink Plasma' is pretty entertaining. It's got a great sense of atmosphere and pleantly of fun little sight gags. It's also pretty amazing that theatrical shorts were still be made in the '70s, although not very many. The Pink Panther was really the last major character used for such a format. Enjoy!