Guatemalan Beaded Lizard

A large, heavy-bodied venomous lizard typically measuring 16–24 inches (41–61 cm) in total length. Body is robust and somewhat flattened dorsoventrally, with a moderately broad head. Dorsal coloration is dark brown to black, with a characteristic pattern of bright yellow, cream, or white beads or rounded tubercles arranged in regular rows across the back, limbs, and tail, creating a striking contrasting pattern against the darker background. The head is covered with similar bumpy scales, and the beaded appearance extends along the entire body and tail. Rostral and labial scales are typically light-colored. Ventral surface is dark brown to black with lighter spotting or blotching. Scales are large, prominent, and strongly keeled, creating a distinctly bumpy or knobby texture. The jaw contains grooved teeth connected to venom glands, a diagnostic feature of this genus. Legs are relatively short and stout, with five toes on each foot bearing claws. The tail is thick and tapers gradually. Primarily inhabits dry pine-oak forests, rocky foothills, and semi-arid highland regions of Guatemala, typically at elevations between 4,000–7,000 feet (1,220–2,134 m). Primarily nocturnal and cryptozoic, sheltering in rock crevices, beneath logs, and in burrows. Diet consists of small vertebrates including lizards, snakes, small mammals, and bird eggs, as well as large arthropods, subdued via envenomation delivered through grooved teeth.

Similar species: Mexican Beaded Lizard (Heloderma horridum) is larger and occupies lower elevations with more humid tropical forests, and has more prominently beaded dorsal scales with broader light bands; Gila Monster (Heloderma suspectum) occurs in southwestern North America and has more rounded beads arranged in distinct dorsal and lateral rows forming a more regularized pattern.