The Grand Teton Beast is an ELK, which is a species of large deer native to North America and Eurasia. ELK are the second largest species in the deer family, with males weighing up to 700 pounds and females up to 500 pounds. They are known for their large antlers, which can reach up to five feet in length. ELK are herbivores, and their diet consists mainly of grasses, leaves, and bark. They are also known for their loud bugling call, which can be heard for miles.