What's the most WTF movie you've ever seen?

One reason we love science fiction and fantasy movies is their wide-open, imaginative spirit. A science-fiction film can go to places that most people can barely dream of. And sometimes... beyond. But what's the weirdest, most inexplicable movie you've ever seen?

Please include a picture, poster or clip from this film. And include the title, year of release, and maybe something about why it's just so, so weird.

Top image: Hell Comes to Frogtown