Gila Monster and Mexican Beaded Lizard: Helodermatidae

Although they are venomous, bites to humans are rare and typically only occur when a person tries to pick up one of these normally slow-moving Gila monsters or Mexican beaded lizards. Both can twist around quickly and deliver a hard bite. Their powerful jaws can remain clamped shut on a finger or hand for many minutes. While a bite can cause awful pain, swelling, and sometimes vomiting and sweating, it is hardly ever fatal. In fact, the last death due to a Gila monster bite occurred in 1930. On the positive side, scientists have found that substances in the venom may be useful in treating human diseases, such as diabetes.