A horror movie is only as good as its villain. There's a reason why the likes of Leatherface, Jason and Freddy became household names while protagonists like Nancy from a Nightmare On Elm Street and, er, that one guy from Texas Chainsaw Massacre 2 whose name escapes me need to be Googled, and that's because audiences remember things they're scared of more than things they're not.
However, while there are plenty of great horror bad guys out there, both new and old, that continue to haunt the dreams of fans, not all of them got a send-off bold and brutal enough to match their reputations. In fact, in a couple of cases these villains went out like such chumps that it undermined any of the terror they might have once dished out, leaving audiences thinking "oh, is that it?" after they were taken down so easily.
Sometimes they came back for a better death in a sequel, but other times the last thing viewers saw of these villains was them disappearing into a wet fart of a death.