Volcan Tacana toad

Preserved individuals have dull brown dorsal coloration with dark brown lateral stripes following the lateral tubercles. There are some cream spots present on legs in some specimens. The ventrum is dark cream with a diffuse dark brown marbled pattern that extends onto the legs. Males generally tend to be more uniform dull brown than the moderately patterned females.

Incilius tacanensis has a small range, being restricted to an area between Cerro Mozotal in Chiapas, Mexico and Zunil Volcano in Quetzaltenango, Guatemala. Even between these points, it has not been recorded from the San Marcos Department of Guatemala. This species may have a larger range than currently known, as it is cryptic and hard to find. The species inhabits leaf litter in moderately high-elevation rainforest and cloud forest, having been recorded at 200–2,200 m (660–7,220 ft). Eggs were present in the oviducts of females collected in July and August, suggesting that breeding occurs in the wet season. Eggs are small and unpigmented, and are laid in clutches of 50–400 eggs.