They modify their habitat through the creation of 'alligator holes', which provide a refuge for other animals during dry periods. These are excavated using both snout and tail. Once these dry out, however, the alligator crosses land in order to find another body of water. Adult males larger than 4.5 m are rare today, but were much more common earlier in the century when 5 to 6 m long males were found. A bony nasal bridge is present.
Older animals lose the yellow banding, and turn dark green and brown.
The ventral surface is a much paler yellow colour. The presence and extent of ventral osteoderms varies with different populations. Eyes are silvery. Captive individuals appear to have broader heads - a possible indication of their more sedentary lifestyle. Dietary range increases substantially as they grow larger, with large adults able to tackle any aquatic or terrestrial prey which comes within range.