There are two types of bad horror films--those that are so dull and atrocious that no one likes them (except masochists or mental patients) and those that are so inept and silly that they are great for a laugh (such as PLAN 9 FROM OUTER SPACE). I would put this one in the second category, though it is a bit duller than some of the cheesy old horror films from the 1950s. I would say that it's more fun than watching ROBOT MONSTER but not quite as much as TEENAGERS FROM OUTER SPACE.
The film is about, you guessed it, a giant gila monster that terrorizes a small town. One by one, it causes auto and train wrecks and then feasts on the inhabitants! While this all sounds very ridiculous and funny, the film actually plays most of the plot very straight. However, inexplicably, it also chooses to insert a lot of 50s rock and roll into the film--even at moments where it makes absolutely no sense at all. For example, near the end of the movie the sheriff finally realizes that the accidents were being caused by the giant lizard but doesn't warn anyone. So, naturally, the teenagers stage a big dance right where the gila monster resides. But to make things worse, even though many people have just died, the lead actor begins to sing (a la Arch Hall, Jr. in EEGAH!)! Huh?! About the only decent thing about the plot was the role of the sheriff. Aside from the big brain lapse mentioned above, he seemed like a nice guy and actually liked the teens and listened to them--not like MOST sheriffs in these sort of movies (like the cops in THE BLOB and INVASION OF THE SAUCER MEN and countless other films who ignore the warnings).
Considering how slowly the gila monster moves in the film, it's a great metaphor for the rest of the movie. Not exactly action-packed but still silly enough to provide a few chuckles to bad movie aficionados--but probably of no interest to others.
By the way, in one scene late in the movie, the sheriff and another local jump into the leading man's jalopy. As they pull out, the shadow of the boom microphone is very clearly seen in the foreground. Considering the low budget and lower expectations for this film, it's not too surprising that they didn't edit this out or re-shoot the scene!