Name of a 1950's sci-fi movie?

I'm trying to remember a Grade B sci-fi movie from either the late 1950's or early 1960's. There was a man from another planet (Davona or something like that) who wore a suit and dark sunglasses (he was light sensitive). He spoke little but carried either a device or creature with a flap that would engulf the heads of people, squeeze and their blood would flow out. Made quite an impression on a 12 year old kid such as myself but cannot recall the title.
Any help would be greatly appreciated. thanks - Gary