Phrynocephalus is a genus which includes 33 species of small and medium-sized agamid lizards, commonly called toadhead agamas or toad-headed agamas, that inhabit open arid and semiarid environments of Asia and Eastern Europe. The systematics of this genus are very complicated with many controversial points of view about the unclear phylogeny of this group. All representatives of this genus have adopted the so-called "sit and wait" hunting strategy and they actively use visual orientation when watching for food. In general, the ecological niche and role of Phrynocephalus species in lizard communities of arid environments of Asia are poorly studied, but seem to be similar to that of Phrynosoma, Cophosaurus, Holbrookia, Uta, and Sceloporus in the New World, as well as Moloch in Australia.
The following 36 species are recognized as being valid.[1]
thumb|right|Phrynocephalus mystaceus in Astrakhan Oblast, Russia.
A binomial authority in parentheses indicates that the species was originally described in a genus other than Phrynocephalus.
"Caup [= Kaup JJ]" (1825). "Einige Bemerkungen zu Merrems Handbuch [= Some Remarks on [[Blasius Merrem|Merrem's]] Handbook]". Isis von Oken 16: 589–593. (Phrynocephalus, new genus, p. 591). (in German).