This is a formidable and large-bodied arachnid characterized by a leg span that easily reaches 5.1 to 5.9 inches (13 to 15 centimeters), while its robust body measures between 1.1 and 1.9 inches (3 to 5 centimeters) in length. Its general coloration consists of a greyish-brown to dull brown tone, covered with dense, short setae that provide a velvet-like texture. A key diagnostic feature is the dark longitudinal band running along its carapace and, most notably, the striking solid black coloration on the ventral side of its abdomen. Additionally, its powerful chelicerae are densely covered with bright red to reddish-orange hairs, which are prominently displayed as a warning signal when the individual feels threatened by potential predators.

Geographical distribution: This species is native to South America, with its primary distribution centered in the southern and southeastern regions of Brazil, encompassing states such as São Paulo, Minas Gerais, Rio de Janeiro, Paraná, Santa Catarina, and Rio Grande do Sul. Its natural range also extends into eastern Paraguay, northern Argentina (especially within the provinces of Misiones and Corrientes), and parts of northern Uruguay. Due to the international trade of agricultural goods, particularly bananas, specimens have occasionally been intercepted in North America and Europe, although these accidental introductions have not led to the establishment of stable wild populations outside of its native Neotropical range.

Habitat: It primarily inhabits the moist and dense environments of the Atlantic Forest, showing great ecological plasticity by adapting well to both pristine primary forests and disturbed secondary forest fragments. The species exhibits a strong synanthropic tendency, allowing it to colonize human-modified environments with relative ease. It is frequently found in banana plantations, where it utilizes the leaf axils and fruit bunches as ideal daytime shelters. In urban and peri-urban areas, it seeks refuge in dark, humid microhabitats, such as wood piles, construction debris, dark closets, shoes, and hidden corners inside human dwellings, which increases the likelihood of human encounters.

Feeding: Operating as an agile nocturnal predator with generalist feeding habits, its diet is mostly composed of various terrestrial arthropods, such as crickets, cockroaches, beetles, and other spiders. Because of its remarkable speed, strength, and highly toxic venom, it is also capable of overpowering and preying upon small vertebrates, including amphibians (frogs and toads), small lizards, and micromammals like rodents. Unlike web-building spiders, it does not construct webs to capture prey; instead, it relies on its acute sensitivity to ground vibrations and a rapid, decisive ambush strategy to subdue its target with a lethal envenomation.

Behavior: This species displays strictly nocturnal habits, hiding during daylight hours to avoid predation and dehydration. It is globally renowned for its wandering nature and highly aggressive defensive displays. When cornered, it does not flee but instead adopts a distinctive threat posture: it raises its two front pairs of legs vertically, exposes its vibrant reddish chelicerae, and sways its body from side to side in a dynamic warning display before delivering a bite. Its venom contains a potent cocktail of neurotoxins that target the central nervous system of mammals, causing excruciating pain, priapism, and severe systemic reactions in humans.

Reproduction: The reproductive cycle begins during the warmer seasons with a complex courtship ritual, where the male performs rhythmic leg vibrations and palpal drumming on the substrate to signal his presence and appease the potentially aggressive female. Following successful copulation, the female constructs a dense silken white egg sac, depositing between 800 and 1,000 eggs inside. The female exhibits high maternal care, actively carrying the egg sac or guarding it fiercely within a secure retreat until the spiderlings hatch. The offspring will go through several successive molts over a period of one to two years before reaching full maturity.

Conservation status: The species has not been globally assessed by the IUCN Red List (Not Evaluated - NE). Given its extensive geographical distribution, high adaptability to human-altered landscapes, and stable population densities in both agricultural and urban zones, it does not currently face any major threats of extinction. Localized mortality occurs due to the intense use of chemical pesticides in agricultural monocultures and targeted eradication by humans fearing its medically significant venom, but these factors do not jeopardize the global stability of the taxon.