Nimbaphrynoides is a monotypic genus of true toads from highlands in the Mount Nimba region of the West African countries of Guinea, Liberia, and Côte d'Ivoire. The sole species is Nimbaphrynoides occidentalis. Along with Nectophrynoides, Eleutherodactylus jasperi, and Limnonectes larvaepartus, Nimbaphrynoides is one of the only anurans that combine internal fertilization with ovoviparity.
Adult males of Nimbaphrynoides occidentalis occidentalis measure on average 18 mm (0.7 in) and adult females on average 20.5 mm (0.8 in) in snout–vent length. Nimbaphrynoides occidentalis liberiensis are larger at respectively 22.4 and 28.7 mm (0.9 and 1.1 in). Adult colouration is variable. The dorsum in most individuals is brown to black backs, without a distinct border between the two colours. It may also be uniform in colouration, or have lighter and darker browns irregularly mixed. There are some lighter areas in the head, at least on the snout and the eye-lids. The legs are light brown with irregularly bordered darker stripes or dots. The venter is typically white, but some Nimbaphrynoides occidentalis liberiensis have small to large light brown dots on their venter. Juveniles had brighter coloured backs than adults.
The male advertisement call is very faint, short, and resembles a metallic "bing". Nimbaphrynoides are viviparous—they have internal fertilisation and the female gives birth to fully developed, tiny toadlets. Eggs are small, ranging from 0.5–0.6 mm in diameter.
