Gila monster (Heloderma suspectum). Photo by Diane Joy Schmidt taken with the cooperation of Craig Ivanyi, assistant curator of Herpetology and Ichthyology at the Arizona-Sonora Desert Museum. The Gila Monster, and the closely related Mexican beaded lizard, are the only poisonous lizards in the world.

From "Outreach UA", The University of Arizona, Volume 2, Number 1