Frank is the main antagonist in Donny Darko. He is very manipulative.
Basically frank is like a hero's sidekick. He helps get things back in order in the doomed universe that was inevitably going to collaps on itself unless he fixed it. With Frank's help Donny is able to save his dimention by making the ultimate sacrifice.
If you are interested in owning of these masks as you can get one off mothergalaxies on etsy or ebay.