Reptiles · Squamata · Helodermatidae

Mexican Beaded Lizard

Heloderma horridum

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

The Mexican beaded lizard — known in Spanish as escorpión mexicano, a regional name, or as lagarto de chaquira — is, along with the Gila monster, one of the few venomous lizards in the world. It is black with yellow blotches and its skin is covered in osteoderms that give it a beaded look. It is slow and nocturnal, and its venom, which it delivers by chewing rather than biting, has proved of enormous medical interest.

Weight

700 g – 4 kg

Size

57 cm – 90 cm

Lifespan

30 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Nocturnal

Active mainly at night.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Easy

RainforestTemperate forestDesertCarnivore Nocturnal Solitary Reptile Rainforest Temperate forest Desert

2countries 14parks1same family

Fun facts

It does not inject its venom: it produces it in glands in the lower jaw and lets it run along grooves in the teeth while chewing, so the longer it holds on, the more venom it delivers.
The venom of its relative the Gila monster gave rise to the GLP-1 analogue drugs, the basis of current treatments for type 2 diabetes and obesity, one of the most profitable cases of bioprospecting in history.
Its skin is covered in osteoderms, small bony plates within the scales, which give it a characteristic beaded appearance and considerable protection.

Life cycle & biology

Skeleton type: Vertebrate - internal bony skeleton (reptile)
Habitat & environment: Dry forest, thorn scrub and ravines of the Pacific slope of Mexico and Guatemala
Sexual maturity: 6 years
Gestation / incubation: 180 days of incubation
Litter / clutch size: 6 eggs

Sources consulted: https://es.wikipedia.org/wiki/Heloderma_horridum