I remember a cover from a Crass single/EP from about 1980 with some really disturbing stuff on it. Haven't been able to find it online (guess it's really out of print), so I can't post it here.
Scariest/goofiest album cover I have in my possession is one by David Clayton Thomas pre Blood Sweat & Tears... Laughably bad imagery combined with way over the top cover notes written by a record company trying to make more substance out of something that didn't have any.