Many Fanged Frogs bear tooth-like (odontoid) processes on their lower jaws, particularly prominent in males. The genus currently contains almost five dozen species. It is well known that this is certainly not close to the true number of species. Many species await formal description. 

Species in this genus have conquered major parts of Asia: China, Indochina, Sundas to Timor I. and New Guinea; also in southern Japan and the Philippines.