Heavy Metal: Watch it when you're high.

Heavy Metal was a 2d animated feature released in 1981. It was rather popular with teen boys in the late 80's when its made it way to television sets and vhs tapes in the backs on video stores. The film mostly revolves around fantastical creatures and boobs. Nuff said. It's actually based off a magazine publication which started in 1974 and is a set of short stories revolving around an evil green ball. 

DO NOT WATCH STRAIGHT. 

First issue of Heavy Metal Dec 1974.

After viewing this forgotten gem immediately go and watch the South Park ep. 'Major Boobage'

 http://www.southparkstudios.com/guide/1203/. Hilarious!