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,
The Lizard in abundance here, but which is found nowhere else in Britain. There are more than 600 species of flowering plants on the Lizard, nearly a quarter of all UK species. The reason for this richness is partly because of the many different and unusual Lizard rocks on the Lizard Peninsula. But above all, it is a coming together of multiple factors: a very mild maritime climate, but one prone to gales and salt winds; waterlogged and boggy soils, but ones that often parch and dry out in the summer; soils of greatly contrasting fertility and pH; and lastly man's influence.