I Eat Your Skin (1964)

Writer Tom Harris is convinced by his agent to research his next trashy romance novel at Voodoo Island.  Along for the trip is his agent, and his agent's shrill wife.  Little do they know, that Voodoo Island is not as innocent as the name would lead you to believe!  Oh wait...

This movie is bad.  Not just for the usual reasons (acting, script, effects), but also because it feels like three bad movies squished together.  Also, it is so bad that the only way they could get people to watch it, was to play it along with the infinitely better I Drink Your Blood; in other words, by holding people hostage.

The first movie is some screwball comedy, with jealous husbands being pushed into swimming pools, and comically escaping from jealous husbands.  I guess you could say the general theme of the comedic parts is "things one does to jealous husbands."  These parts of the movie take up only the first and last five minutes or so (though they feel like hours).

The second movie is a decent zombie survival horror movie, with people trapped in bad situations and a surprisingly gory decapitation.  This part of the movie is pretty good, but it only lasts for twenty minutes or so.

The third movie is your typical "we've got no budget, stand around and talk forever" scifi movie from the late 50s.  Unfortunately this takes up most of the movie.

So what you end up with is like a tootsie roll pop.  On the outside is a thin layer of candy (screwball comedy).  Underneath that is a bunch of tootsie roll (the scifi parts).  Then in the middle you have... uh... more tootsie and that's like... hmmm

So what you end up with is like a Russian doll.  You open up your screwball comedy, and there's a boring scifi movie inside!!!  Then you open that, and there a zombie movie!  Then you open that and... you are back to the... scifi movie... because inside the smallest Russian doll is a... portal or vortex... that allows the scifi movie Russian doll to exist both within and without the zombie doll... hmm...

I'm not sure what it's like, but since the only way to find out would be to watch the movie, I don't recommend attempting this.