Although this species is principally fossorial, it also has aquatic habits. It has been reported to prey on large surface animals, including cattle, by suddenly capturing them from below the water.
It is thought to be a burrowing animal, producing enormous trenches as it digs, which suggests a body diameter of up to ten feet. Its body length is stated to vary, from 75 up to 150 feet. There have been cases of houses and other man-made structures collapsing, and rivers having their course altered, allegedly due to the minhocão's burrowing activity. These tunnels most commonly appear after periods of continuous rain, indicating that the minhocão is more active during such periods, and might even keep itself hidden during dry days. The beast's tunnels will sometimes flood, creating subterranean water bodies.
Cryptozoologist Karl Shuker has suggested that this animal may be an example of a giant caecilian. Caecilians are a poorly known group of amphibians with worm-like, limbless bodies, subterranean/aquatic habits and tentacle-like sense organs on the head. Also, most caecilians do inhabit the forests of South America. which fits the description of the minhocão well. However, known caecilians do not even begin to approach the supposed size of this animal.
In On the Track of Unknown Animals, Bernard Heuvelmans suggests that the animal may be a surviving glyptodont. However, unlike their modern relatives, the armadillos, there is no evidence that glyptodonts had burrowing habits. Whatever kind of creature the minhocão was, if real, it appears to be extinct now, as there have been no reported minhocão sightings in the past 130 years.
See also: Mongolian Death Worm, another worm-like creature.