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,
Mexican beaded lizard (swelling), weakness, sweating, and a rapid fall in blood pressure. Beaded lizards are immune to the effects of their own venom. Some compounds in its venom have been shown to have pharmacological properties relating to the possible treatment of diabetes, Alzheimer's disease, and even HIV. One compound, a hormone named exendin-3, is marketed by Amylin Pharmaceuticals as the drug exenatide. A study in 1996 revealed that it binds to cell receptors in breast cancer cells and may stop the growth of lung cancer cells. The beaded lizard becomes sexually mature at six to eight years and mates between September and