It might be a little misleading, but Caltiki is not the name of the monster even though the characters of the film call it as such, but it is the name of a Mayan goddess, one whose statue guards a lake where human sacrifices were made in her name. In that lake are many skeletons all ripe with gold and other fine treasures, victims of the goddess from many years past. Yet in that lake resides the creature which killed those men and women and as a group of archeologists get a little too greedy for their own good, they awaken said creature and are attacked because of it. After defeating the monster they fail to realize that a piece of it still exists and after transporting it home and discovering their charge, they decide to keep it much to their regret.
Caltiki, il mostro immortale is a giant monster film whose creature is just a mass that can grow exponentially when exposed to radiation. The closest comparison would be to the movie The Blob with Steve McQueen yet this Italian horror film is far more exciting than The Blob ever was. This creature is also just a little bit more frightening as it not only digests its victims but spits the bones out too, or at least so much as it is able to spit. What is also a little surprising is just how well the monster looks on screen as there were some great special effects in play to make it seem like a real, plausible threat. It may be just a very large, man-eating, blob of a monster and look somewhat unassuming but it is that deceptive exterior that is so dangerous and a little scary. Sometimes an uncaring and assumedly unfeeling villain is the one to watch out for as there is nothing holding them or it back from killing you.
The best thing about this film is just how well it flows and how gripping it turns out to be. There is very little downtime in the film as the pace rarely lets up, but when it does it is not for very long. Writer Filippo Sanjust injects a lot of tension and suspense into the film and whenever the creature is about to put in an appearance that suspense becomes just a little more palpable. It helps that the film is filled with some actors who know what they are doing, specifically John Merivale as Dr. John Fielding. He tries to make everyone aware of exactly what is happening, what the creature is capable of and that if people do not take action soon, then it may be too late for all of them.
Directed by Riccardo Freda, he does a great job of keeping you interested from start to finish and while his name is the one the film is most associated with, some say Mario Bava had a hand in helping to finish the film. Whether it was directing or editing the story changes depending on who you ask or where you read about it but whatever the case, the film turned out exceptionally well. Caltiki, The Immortal Monster might not be as frightening as other films, but it is a lot better than The Blob which is somewhat similar and as far as giant monster movies go, while it is no Godzilla, it does all right standing on its own.