Paraguay has its myths and legends but one of the strangest ones is the story of a creature called Mboya Jagwa, dog snake, a water serpent 60 or 70 feet long with a head like a dog and a hooked tail. The local people all agree the description of it, and one village was said to have moved to another part of the country because one of these creatures had settled nearby.
So a huge water serpent which is said to attain a length from 60 to 100 feet. It is unknown to modern science, although one white man now living in Paraguay is said to have discovered a huge skeleton on the banks of a Riacho in the Choco. He did not realise the value of his find, and took no steps to preserve it. The Indians describe the creature as having a head like a dog, and as carrying that similarity still further by yelping like a puppy.
“I have heard the story of an Indian who was attacked by one in crossing a little river in the central (arid quite populated) part of Paraguay. The serpeant swam swiftly towards the frightened man, and swirling in the water attempted to envelop his victim in the coils of his tail. The old man escaped this fate only by diving and escaping to the shore.
All the Indians, the Paraguayans, and the Correntinos of the North of Argentina vouch for the existence of this horrible animal, and agree down to the smallest details in their descriptions of the creature and its habits. I have known an Indian village to be moved to another part of the country on account of the terror inspired by an "Mboya Jagwa" which had taken up its abode at the river crossing in front of their "toldos."
In the Cordilleras, stretching from Villa Rica to the Rio Parand, people describe a probably extinct monster called the Tiger Jaguar (Iguana-Dog)—a creature with the head and tail of an alligator and the body of a dog. Now, these people have never had access to words of geology, so cannot know that they are giving a fairly accurate description of the "Dinosaurus," which existed in Colorado and Nebraska in immense numbers during other geological periods”
Could there be an ancient type of large snake living in Paraguay? It is always possible with new creatures being discovered all the time and some that were thought to be extinct re-appearing. Boa Constrictors are common there so another type of snake could also survive there. I wonder if any modern day sightings will turn up or will it remain just a story.