Final answer:
The Gila monster is one of the only venomous lizards found in the United States. It possesses venom glands and delivers venom through a bite. Its fat tail serves as a water storage organ, an adaptation to arid environments.
Step-by-step explanation:
The Gila monster is a notable species as it is the largest and one of the only venomous lizards found in the United States. Contrary to some belief, it is not poisonous, but venomous, which means that it has specialized glands capable of producing venom. This toxin is delivered through its bite rather than being poisonous, which implies causing harm when ingested or touched. Most lizards are carnivorous, and while some large species like iguanas are herbivores, the Gila monster, along with the beaded lizard, is traditionally known for its venomous capabilities.
Their fat tails serve as an adaptation to their arid habitats, allowing them to store water and survive in dry climates. It should be noted that although traditionally considered to be one of the only venomous lizards, recent discoveries have shown that venom glands are also present in some monitors and iguanid species. However, their method of delivering venom is not as direct as the Gila monster's. The Gila monster's venom is a defense mechanism rather than a way to subdue prey, making them less aggressive compared to other predators like the Komodo dragon, which will actively attack large animals including deer and, on rare occasions, humans.