Exhibits a robust yet slender body design characteristic of Tropidurus etheridgei, with adult individuals reaching a snout-vent length (SVL) of 80 to 105 mm, where males are characteristically larger and more robust than females. Its dorsal coloration is predominantly grayish-brown or olive-brown, adorned with a variable pattern of dark, chevron-like spots or diffuse transverse bands that provide exceptional cryptic camouflage against tree bark and stony soils. The dorsal scales are strongly keeled and imbricate, giving the skin a rough texture and offering effective protection against water loss. Pronounced sexual dimorphism is present; adult males display prominent patches of deep black or dark gray on the throat and the sides of the belly, often highlighted by bright yellow or orange hues along their flanks during the breeding season, whereas females and juveniles retain a more uniform and cryptic brownish coloration.

Geographical distribution: This species is widely distributed across the central dry regions of South America, primarily within the Gran Chaco biome. Its geographic range encompasses northern and central Argentina (including provinces such as Salta, Formosa, Chaco, Santiago del Estero, Tucumán, Catamarca, Santa Fe, and Córdoba), western Paraguay, southeastern Bolivia, and southwestern parts of Brazil, particularly in the states of Mato Grosso and Mato Grosso do Sul, where it inhabits ecotones bordering the Pantanal.

Habitat: Primarily occupies dry deciduous forests, woody savannas, thorny scrublands, and ecological transition zones characterized by a highly seasonal climate. It displays semi-arboreal and saxicolous tendencies, frequently utilizing fallen logs, rock crevices, rough tree bark, and deep leaf litter as essential microhabitats. It also adapts well to low-intensity human-modified environments, often found basking on wooden fence posts, stone walls, and rustic rural structures.

Feeding: Maintains an insectivorous and opportunistic diet, functioning as a classic sit-and-wait predator. Ants (formicids) constitute the vast majority of its prey, making it a specialized consumer of these insects, although it regularly complements its diet with beetles (coleopterans), grasshoppers (orthopterans), insect larvae, spiders, and other small terrestrial invertebrates available within its home range.

Behavior: This is a strictly diurnal and heliothermic lizard, relying heavily on direct sunlight to regulate its internal body temperature, which makes it highly active during the hottest hours of the day. It is extremely territorial and social-dominant; males defend their basking territories vigorously through stereotypic visual displays, including rapid vertical head movements (head-bobbing), body push-ups, and the expansion of the gular region to deter rivals or court females.

Reproduction: An oviparous reptile whose reproductive cycle is closely tied to the warm, wet season of spring and summer in the southern hemisphere. Females reach sexual maturity within their first year and typically produce one to two clutches per year, depositing between 3 and 8 soft-shelled, elliptical eggs in shallow underground nests dug in sandy soils or concealed beneath decaying logs. The incubation period depends on environmental temperatures, generally lasting between 60 and 75 days before the independent hatchlings emerge.

Conservation status: It is currently listed as Least Concern (LC) on the IUCN Red List, owing to its vast geographical distribution and relatively stable population trends. Nonetheless, local populations face localized pressures due to habitat fragmentation, wildfires, and extensive deforestation driven by agricultural expansion within the dry Chaco ecosystems.