This is a small to medium-sized squamate reptile characterized by a cylindrical body and a remarkably robust, short, and wide head that is highly distinct from its neck, giving it a somewhat blunt, rounded profile. Adult specimens typically measure between 14 and 22 inches (35 to 55 centimeters) in total length, with exceptional individuals reaching up to 27 inches (70 centimeters). Its dorsal ground color ranges from shades of pale brown, gray, or light tan, adorned with a series of dark brown or blackish transverse blotches or bands that may alternate or fuse along the vertebral line. The ventral surface is mostly whitish or yellowish, peppered with irregular dark spots. It features large eyes with striking vertical, elliptical pupils, which are a key evolutionary adaptation for its crepuscular and nocturnal lifestyle. Its dentition is aglyphous and highly specialized, completely lacking venom, and evolved specifically to grab and extract gastropods from their shells.

Geographical distribution: This species is widely distributed across central and southern South America. Its geographic range covers vast territories including northern and central Argentina, the entirety of Paraguay, western Uruguay, eastern and southeastern Bolivia, as well as the central, southern, and southeastern regions of Brazil, particularly in states such as Rio Grande do Sul, Paraná, São Paulo, and Mato Grosso do Sul.

Habitat: It primarily inhabits a diverse array of terrestrial ecosystems, including semideciduous forests, gallery forests, humid savannas, and semi-arid scrublands like the Gran Chaco and the Cerrado. Additionally, it exhibits high tolerance to human-modified landscapes, frequently occurring in agricultural fields, rural pastures, and suburban areas, where it occupies backyard gardens and damp orchards that host high densities of its prey.

Feeding: It displays an extremely specialized malacophagous diet, feeding almost exclusively on terrestrial gastropod mollusks, mainly snails and slugs from families such as Bulimulidae and Veronicellidae. Thanks to highly flexible cranial and mandibular adaptations, which allow independent movement of its jaw elements, it inserts its jaws into the snail´s shell and, using alternating movements of its recurved teeth, pulls the soft body of the mollusk out of its calcareous shell without breaking it.

Behavior: This snake is predominantly nocturnal and crepuscular, exhibiting slow and deliberate movements primarily on the ground (terrestrial), though it can occasionally climb into low vegetation (semi-arboreal). It is entirely harmless and non-aggressive toward humans; when threatened, its main defensive strategies include coiling its body tightly, hiding its head beneath its coils, or flattening its head to mimic a venomous lancehead species, alongside discharging a foul-smelling musk from its cloaca. During the colder winter months of its temperate range, it undergoes a period of winter torpor or inactivity.

Reproduction: This reptile employs an oviparous reproductive strategy. Breeding activity is highly seasonal and strongly synchronized with the warm, rainy months of spring and summer, which align with peak snail availability. Females reach sexual maturity at slightly smaller sizes than males and lay clutches that typically range from 3 to 10 elongated, leathery eggs. These eggs are deposited in moist, sheltered microhabitats, such as decomposing logs, soil cavities, or under dense leaf litter, where appropriate temperature and humidity levels are maintained until the hatchlings emerge.

Conservation status: It is currently classified as Least Concern (LC) on the IUCN Red List and in most regional conservation assessments. This status is supported by its expansive geographic distribution, stable populations, and remarkable ecological plasticity in human-disturbed habitats. Nonetheless, local populations face minor threats such as vehicular mortality on roads, habitat loss due to agricultural expansion, and direct killing by humans who mistake this harmless, beneficial snake for a venomous species.