What is the name of the fold of skin hanging from an animal's neck?

The fold of skin hanging from an animal's neck is commonly referred to as a "dewlap." This feature is found in various species, including some reptiles, amphibians, and mammals, and serves purposes such as mating displays, thermoregulation, and territorial signaling. In certain animals, like the American bullfrog or specific lizards, the dewlap can be enlarged and prominently displayed during courtship or to assert dominance.