Mexican Beaded Lizard Profile and Information

Mexican Beaded Lizards

The Mexican beaded lizards are giant reptiles that are one of only two venomous lizards in the world, the other being the Gila monster. Both female and male Mexican beaded lizards possess broadheads, with the males’ being broader.

They have small, bead-like scales that are don’t overlap. Most of the scales on their body are underlaid with bony osteoderms, apart from their undersides.

They can be characterized by their overall black color with varying patches or bands of yellows, while some of them are all-around black. The Mexican beaded lizards can smell with the help of their pink, forked tongue.

They flicker their tongue and use it to gather scents, then touch the organ known as Jacobson’s organ that gives them the information they need.


  • Kingdom: Animalia
  • Phylum: Chordata
  • Sub-phylum: Vertebrata
  • Class: Reptilia
  • Order: Squamata
  • Family: Helodermatidae
  • Genus: Heloderma
  • Species: Heloderma horridum
  • Population size: Unknown
  • Life span: 20 to 30 years
  • Weight: 800 G
  • Length: 57 to 91 CM
  • Scientific name: Heloderma horridum


Mexican beaded lizards can be found in southern Guatemala and Mexico. They live in thorn scrub forests, tropical deciduous forests, tropical scrubland, and pine-oak forests.

Habits and Lifestyle

The Mexican beaded lizards are mostly active from early April to the middle of November. These lizards spend about an hour every day above the ground. They are classified as semi-arboreal reptiles that can climb on trees at night to search for food.

They hide under rocks or burrows during the day and hunt for food at night using their venom to weaken predators, paralyze and kill their prey. They usually give off warning hisses when threatened.

Diet and Nutrition

Mexican beaded lizards are carnivores, and they feed primarily on reptile eggs and birds. They also hunt mammals, small birds, other lizards, little rats, frogs, insects, and insects. Apart from eggs that they have to break first, beaded lizards swallow their prey whole.

They are also able to survive on the fat stored in their tail, but they do this when food is very short supply. Unlike most lizards, the tail of a Mexican beaded lizard doesn’t autotomize and can’t grow back if it’s broken.

Mating Habits

Mating season of Mexican beaded lizards usually occurs between the month of September and October. Male lizards would engage in physical combats during mating season, and this ritual fights could last for many hours. The victor then mates with the female.

A female beaded lizard may lay clutches of 2 to 30 eggs. It takes about 6 to 7 months for the incubation process to be over.

Young beaded lizards are rarely seen. They usually spend much of their early lives below ground and surfacing when they are two or three years old when they are grown to a reasonable size. They reach sexual maturity at 6 to 8 years.

Population threats

The myths and superstitions surrounding the Mexican beaded lizards are incorrectly believed, and some include the fact that the lizards can cause lightning to strike using their tails or that they are more poisonous than rattlesnakes.

Because of this false superstition, the lizards are often killed when spotted by the locals.

These rarely-seen lizards are also illegally caught and sold into the exotic animal trade. Mexican beaded lizards do not reproduce well when in captivity, and collectors make more money when they are scarce, making them one of the rarest lizards on earth.

Conservation status

The total number of the Mexican beaded lizard is yet unknown according to the IUCN list. Nevertheless, the estimated population of the Guatemalan beaded lizard is around 350 mature lizards.

Presently, the species is classified as LC (Least Concern), but its numbers are gradually decreasing.

Other facts about the Mexican beaded lizards

  • Mexican beaded lizards are one of two venomous lizard species. They possess unique grooved teeth they use in releasing venom when they bite. They typically bite their venom into their prey.
  • There isn’t any anti-venom for the Mexican beaded lizard.
  • These lizards would hiss and gape when they feel threatened. They typically use their venom to subdue or weaken predators like raptors, coyotes, and even humans.
  • Beaded lizards in their natural habitat need higher humidity than other reptiles in the desert.
  • These are nocturnal lizards that hide in burrows and rocks during the day and become active at night.
  • They may appear sluggish but are able to move at great speed when provoked. Are there other facts about the Mexican beaded lizard you are aware of and would like to share with us? Have you ever had contact with at least one of these big boys? Kindly share your thoughts in the comments below.
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