Rio Magdalena Monster
The Magdalena River is the principal river of Colombia, flowing northward about 1,528 kilometres (949 mi) through the western half of the country. In the rainy season, the Rio Magdalena in Colombia creates a vast area of wetlands. But now its flood plains are threatened by climate change, agriculture and logging.
In 1921, travellers along the northern part of the Rio Magdalena river claimed to have seen a large reptile that resembled an Iguanodon. This sighting is mentioned Karl Shuker’s book, ‘In Search of Prehistoric Survivors’.
There are West Indian Manatees in the river ,although now in danger of extinction. Could it have been one of these seen grazing on the banks of the river?
Had it been more recently there is a mundane explanation.
It was in 2007, 14 years after Escobar's death, that people in rural Antioquia, 200 miles north-west of Bogota, began phoning the Ministry of Environment to report sightings of a peculiar animal."They found a creature in a river that they had never seen before, with small ears and a really big mouth," recalls Carlos Valderrama, from the charity Webconserva.He went to look, and found himself faced with the task of explaining to startled villagers that this was an animal from Africa. A hippopotamus.
Escobar, a reported drug lord, had Hippopotami on his ranch in a sort of zoo, some of which escaped.
The El Fosil museum in Villa de Leyva houses some wonderful artifacts. These include several fossils found in the area, including a 120 million-year-old skeleton of a dinosaur. So dinosaurs had roamed the region in the ancient past. There have been no more reports so could it have been mistaken identity?
The San Miguel Lagoon Creature
In 1971, a creature was seen in a lagoon in Havana, Cuba. The lagoon, a flooded quarry, is in San Miguel del Padrón, a suburb of Havana. Descriptions varied from a spindle-shaped creature , with large and threatening yellow eyes,to a horned, hippopotamus-like animal with a featureless face. According to one witness who claimed to have seen the animal on multiple occasions: “It doesn’t look like anything but a black ball that, maybe, resembles a hippopotamus with horns, but it doesn’t really resemble any animal…and it’s got no eyes on it at all.” The government radio station, Radio Progresso, sent reporters to investigate. One of the reporters sent to investigate the phenomenon claimed he saw the creature. He said he saw something rise from the water amid “intense bubbling.” It had a rough texture and a rounded shape. After it surfaced, it floated for a few seconds, and then sank back into the water.
There appears to be no recent reports nor any answers to what it was. However I found this from 2012 which says a tree trunk was found some time later:https://oncubanews.com/en/magazine-articles/creature-san-miguel-lagoon/
It is possible for a tree trunk to surface with much bubbling and to sink again....or was it an unknown creature ? Sounds a bit like a giant shelled creature ,which sometime showed its shell, other times its body. Unless the lagoon is drained we shall never know.