Large males' femoral pores are 2 to 4 times greater than those of females of equal size. Flap under the neck is stiffened during head-bobbing display. Males secrete a fluorescent substance from glands in their legs. May be used to communicate with others and mark their territories. Females are lighter and more greenish, smaller, with smaller head and shorter dorsal spines.
Juveniles have yellow-bordered black spot on their eyelids.
Adults can run bipedally on land. Juveniles can run on land and over water. Mainland Central and South America. Near large bodies of water. Sleep in trees or rock crevices, emerge and bask for an hour, then search for food the rest of the time.