This is one of the funniest Rifftrax movies I've seen, but the movie itself is somewhat bizarre (though I suppose that this is to be expected). A scientist named Dr. Gilbert McKenna (Robert Clarke) is exposed to nuclear radiation at his laboratory. For undisclosed reasons this turns him into a monster when he is left out in the sun too long. Interestingly this only affects half his body as he also runs around in totally soaked khaki pants. And no, it's never explained why his pants are soaked either. McKenna spends most of the movie alone in his secluded house on the California coast, driving to bars, and rampaging. It's your typical poorly made, low budget, campy horror film from the 50's. Other interesting things about the film include the music which also appears in Night of the Living Dead. Since that film was made 9 years later I'm going to guess that it's probably stock. Other than that there's not much else to write. Except, of course, that the Rifftrax is hilarious.

Dr. Gilbert McKenna (Robert Clarke) is a research scientist who is accidentally exposed to a new type of radiation. At first, he seems to be doing remarkably well. However, once in direct sunlight, Gil's body begins to change. He goes through a devolution process and turns into some sort of out-of-control, lizard-type creature. "Hideous" is the right word to describe Gil's transformation. The special effect suit is about as good as I've seen in a 1950s era sci-fi/horror film. I'd rate it right up there with the suit from Creature from the Black Lagoon. It's really nicely done. The acting is hit or miss. Clarke does a good job playing the tortured victim. I also enjoyed Nan Peterson as Trudy Osborne - not because she's a particularly great actress, but she channel's Marilyn Monroe quit well. Some of the performances, however, are laughable. I'm thinking of the dude who played the gangster - I think it was Peter Similuk. Just awful. The problem with The Hideous Sun Demon and the thing that keeps me from rating it higher is there's really not much plot here. The movie is full of padding. The runtime is only 74 minutes, but I'd bet at least 20 of those minutes felt like filler. For example, I think there are more scenes of people driving around California than there are scenes devoted to the titular Sun Demon.

Though a lot of people might say otherwise, Robert Clarke's cult sci-fi horror/monster movie is actually quite good. With some good performances from the lead characters, even though the explanation behind the monster is ridiculous the film itself is quite entertaining with what seems to be an imaginative spin on the werewolf legend. The monster itself is very good and convincing with some good cinematography giving it a sun baked feel to it. Although the film is not at all scary and hammy at times, its fast pacing, occasionally intense acting, and wonderfully designed monster costume make this one of the better low budget monster movies of the 50s.

While not the great classic, this movie does have a solid place in '50s sci-fi movie. The plot is pretty original, and I can see why a person would be in lot of trouble if he turns into a reptile as soon as he's exposed to sun. I watched this movie on TV when I was a kid and have been looking to find it for some time. Now it's up on Youtube, and I've seen it after over 40 years. What interested be after watching was of course the plot which I didn't understand when I was a kid, and also the gas station scenes. The gas was going for $.27 per gallon, and it was full service back then. Another thing is that people smoked a lot more then than now. It's not bad of a movie for one man to produce, star and direct, and I give Robert Clarke high score for the attempt. For one who didn't live that time or seen this movie back then, this movie probably don't mean much, but watching it now, I see that people really were different back then, and this movie brings back memories of how things were.