Then there is the monster flick said to be based on real monster attacks.
Monstroid (AKA Monster) is a 1979 flick writtern and directed by Kenneth Hartford and starring John Carradine and James Mitchum. I think the budget was blown on getting hold of John Carradine as the film looks ultra-cheap. Herbert L. Strock began shooting the film in 1971 but never finished it and the project was later handed over to Hartford.
If you can ignore the sub-Rentaghost acting and abysmal special effects then it’s not a bad story. It is set in a small lakeside town in Colombia. The town’s main employer is a large US cement company whose works have been polluting the lake for years killing off all the fish much to the anger of local fishermen. An activist, incensed by the pollution, is spreading anti-US sentiment in the area and a reporter from America is covering the pollution story, showing the company up in a bad light. One woman claims that her husband was devoured by a monster from the lake several years ago, but no body was ever found and she is looked on locally as a witch. Carradine, the town priest, thinks the monster is of a diabolical nature.
The cement company send down one of their executives to investigate the goings-on. Shortly after he arrives there is a spate of killings in and around the lake, where victims are attacked and eaten by some kind of animal. The children of an American secretary photograph the monster and the company executive, the reporter and the town mayor have to join forces to come up with a plan to stop the beast.
The creature itself looks like Kermit the frog if he lived in Sellafield. Imagine a grey/green, scaly, long necked walrus, sans the tusks but with crocodile teeth, feet and tail, a catfish's barbles and a cat's eyes, then you will have a good idea of what the creature looks like. It is realised by a shockingly unrealistic hand puppet and a full sized head and neck and whole head, neck and body models operated in the water from beneath.
At the start of the film we are told that the movie is based on real events that took place in a lake in Colombia in June 1971! I have never heard of a killer lake monster in Colombia in June 1971 or at any other time for that matter.
The town in the film is referred to as Chimayo and the movie was apparently filmed on location there. However, there is no Chimayo in Colombia. There is a Chimayo in New Mexico that has a small lake several miles to the west of it. Monstroid was partially shot here.
According to local folklore an important Christian pilgrimage site in New Mexico is the Sanctuario at Chimayo, which is visited today by thousands of pilgrims, especially during Holy Week. According to local tradition, the site was an ancient, pre-Christian shrine associated with twin war gods who killed a child-devouring monster on that spot. As a result of the death of the monster, a pool of healing mud was created. But this hardly seems like the 1971 events we are told of at the start of the film.
Acorrding to the credits it was also partially filmed in Ambalema, Colombia. This is a town in the Tolima department of central Colombia. There seems to be no large lake in the area but the Rio Magdalena runs right next to the town. I can find no record of a monster or attacks by one on the river. Could we be dealing with attacks by a known animal such as a black caiman, bull shark or anaconda?
The cover to the video release of the film confuses matters further by proclaiming that ‘This film is a re-enactment of four days of terror that rocked the small village of Chimayo, Colombia.”