Horror Film with Warning Bell When Scary Parts Are Coming

Please help if you can. I have been searching for the title of this movie for several years.

I'm looking for the title and the actual DVD of a horror/monster movie from the 1970s (if it's available) which featured a swampy-blobby like creature who talked with a speech impediment, AND a warning alarm during the scary or violent scenes.

I remember that at the end of the scary parts, a "ding-dong" sound was used to let you know the frightening scene had ended.

It was a really bad movie, and we would love to get our hands on it again to laugh at, if we can ever find it. I know it was a long time ago, but if you can help in any way it would be very much appreciated. Thank you in advance.

Sam