Creating a Preloader

I need some help with a preloader. I can build the simple bar preloaders but I am having trouble making a custom one. I am wanting the loader to fill upwards instead of left to right. I am not having any luck with it. I attached the skull that I am using. I want the nose and eyes to fill in red as the page loads. Everytime I try to add in the skull the loader bar and text disappears.

Thanks for the help.