Mexican beaded lizard

Latin Name
Heloderma horridum




30 inches from head to tail, the Mexican beaded lizard's head is broad and flat with venom glands at the lower jaw. Body is long and heavy, but not quite as stout as that of the gila monster. Scales are bead-like and form a pattern of yellow and black stripes; one subspecies is completely black.



Throughout western Mexico


Protected under the Convention on International Trade in Endangered Species. Lincoln Park Zoo participates in the Mexican Beaded Lizard Species Survival Plan®, a shared management effort by zoos throughout the Association of Zoos and Aquariums.


Found in dry, open forests with abundant rocks and sparse vegetation. Burrows to avoid the midday heat.


Carnivorous: eats insects, spiders, other small invertebrates, lizards, snakes, rodents, birds and eggs. Primarily terrestrial. They are frequently found in abandoned mammal burrows and near sources of permanent water. Preyed upon by large mammals and birds of prey.

Life History

Mating occurs mostly in the spring. Between 3-13 eggs laid in mid-to-late summer and buried in sand at a depth of about 5 inches. Incubation is 117-130 days.

Special Adaptations
  • Paired salivary glands produce a venom injected through a groove in the teeth that paralyzes prey.
  • Must chew their victim in order to inject venom.
  • The tail is used to store energy for times when food is scarce.
  • Long claws are used for digging.
  • Tongue used as a sense organ.

Lincoln Park Zoo Exhibit