Whatever the title of this one is (the copy i saw was titled "Swamp of the lost monster," and had a video print that looked like it's film stock had been soaked in urine and scraped by steel wool) it's a pretty bad little Z grade horror/mystery/western about a fey looking cowboy who rides into town with his seemingly indestructable comic sidekick and stumbles onto a mystery involving an insurance scam, bandits, horse dancing, and a goofy looking monster who emerges from some of sickest, most opaque "water" I've ever seen. Seriously, the dude who wore that suit better have recieved some kind of shots after filming, because I'll bet a thimble full of that stuff would have given you digestive problems for quite some time.
I've always found that making fun or heaping scorn on one of these zipper monster movies is just too easy, and kind of a waste of time. I mean sure the movie is bad, but, aren't all examples of this particular subgenera of horror lame?
So once again, it's bad. But you should have been able to tell that even before you handed over your rental card.