Gila monster Gila monster The Gila monster ("Heloderma suspectum", ) is a species of venomous lizard native to the southwestern United States and northwestern Mexican state of Sonora. A heavy, typically slow-moving lizard, up to long, the Gila monster is the only venomous lizard native to the United States and one of only two known species of venomous lizards in North America, the other being its close relative, the Mexican beaded lizard ("H. horridum"). Although the Gila monster is venomous, its sluggish nature means it represents little threat to humans. However, it has acquired a fearsome reputation, and is sometimes killed despite
Mexican beaded lizard three species overlap, making them sympatric. The Guatemalan beaded lizard ("H. charlesbogerti") is the only allopatric one, separated from the nearest population ("H. alvarezi") by 250 km of unsuitable habitat. The Guatemalan beaded lizard is the most endangered of the species, if not of all lizards; it is found only in the dry valley of the Río Motagua in northeastern Guatemala; less than 200 are believed to exist in the wild. The beaded lizard is a specialized vertebrate nest predator, feeding primarily on bird and reptile eggs. A semi-arboreal species, it is found climbing deciduous trees in search of prey