Mexican beaded lizard generic name "Heloderma" means "studded skin", from the Ancient Greek words "hêlos" (ἧλος)—the head of a nail or stud—and "dérma" (δέρμα), meaning skin. Its specific name, "horrĭdum", is the Latin word meaning rough or rude. The four subspecies of beaded lizard, elevated to full species in 2013, are: Adult beaded lizards range from in length. They are substantially larger than the Gila monster, which only reaches lengths of . The snout-to-vent length of a beaded lizard averages . The average body mass of an adult beaded lizard is , about 45% heavier than the average mass of a gila monster,
Greater short-horned lizard widely distributed lizard in North America and occurs in the widest range of habitats: West into central Nevada, East into North and South Dakota, North to Southern Saskatchewan and Alberta and then South into the Texas Panhandle and into central Mexico. This species of lizard is mostly an arid mountain dweller living in the range of 9000–11,300 feet (170–3440 m). It is the only member of its genus in Wyoming, which counts "Phrynosoma" as its state reptile. It is also considered an endangered species in Saskatchewan and Alberta. The greater short-horned lizard occupies ranges from semiarid plains to high elevations