Horror Film Villains

Good afternoon!
I decided to do further research into villains as in order for my horror film to be successful, I need the villain to be as scary as possible without over-doing it. What I mean by this is that I want the villain to be shown firstly as someone or something we can empthatise with but then a major twist so in the end the audience feel hatred towards the character. Baring this is in mind the first thought that came up was children but the only problem I may have with this in future is seeking out children who will be willing to act for the trailer. My horror trailer on the whole has to be able to affect the audience in a way that gets them talking about the trailer and if it were a real film, make them want to see in near future. Going back to villains, YouTube was my main source for researching what villains has scared the public the most. I watched this video on YouTube which is made by a random user, conveying what he/she feels as the most scariest villains:



Although I am a total 'woss' when it comes to horror films, seeing these villains made me jump at first but then I got use to the way the villains looked and then they didn't seem as scary as I first made them out to be. Most of the villains on here are humans but have been disfigured or wearing some sort of costume or face mask which makes them appear scarier. I believe this effective because then it makes the audience more 'in edge' as seeing human killers is deemed as more scary than monsters (due to my current questionnaire feedback) as there is a greater chance of seeing them in real life. Comments on the video have been:

I find these comments interesting because they have all watched the same video and yet there are different views on it. I particulary find the last comment fascinating because they are scared as the film was based on a true event. Perhaps for my trailer, I should find a horrific event that has happened within history and base my film around that; maybe it would heighten the interest of people who would want to see the whole film. However personally, I do find human killers scarier than monsters as there is always that concept of them being real within real life rather than fantasy monsters like vampires trying to hunt people down. Additionally, it would be easier to incoporate a human killer within my trailer and on the whole would make the ordeal easier to film.