Food and Drink Blog: What is the mythical female creature that sucks the life force of men?

I cant remember it, but its either female or it takes on the form of females I think, please help, Its really bugging me and I cant seem to find it through google, yahoo, or any other search engine, I even looked through a list of female mythical creatures one by one, and there were over 1000 entries -,-

Know better? Leave your own answer in the comments!