The Kaadu are a terrestrial, reptavian species native to the planet Naboo. In the wild, this bird-like species is typically seen only in large herds. The largest Kaadu herds can reach up to a million individuals. Herds of this billed creature move expeditiously across the open plains of Naboo. Xenobiologists have recorded groups of Kaadu moving at speeds up to eighty kilometers per hour. Much like other reptilian species, the Kaadu are cold-blooded. These majestic animals can grow to a height of around two meters. The scale-like skin of the Kaadu is typically a shade of yellow or orange, and males of this species are darker in color than females.
In both avian and reptilian fashion, the Kaadu are oviparous; with the females grouping together and laying as few as one hundred eggs and as many as two hundred and fifty eggs per clutch. Kaadu have been documented either building raised nests of mud in the swamps, or in the long grass of the expansive Naboo plains. Many xenobiologists believe that the Kaadu are terrestrial creatures with specific adaptations that allow them to flee to the water in times of danger or while foraging for aquatic plants or snails. Many theorize that foraging in these underwater environments facilitated the Kaadu's evolution into a more amphibian species. An example of these specialized traits are the Kaadu's immense lung capacity and its bill. These two adaptations, plus its more than proficient swimming abilities, allow this large reptilian creature to flee predators or forage under the surface of the water for up to two hours.
Cultural anthropologists are often quick to note the reliance that the Gungans have on the Kaadu. For a great number of generations, the Kaadu have been the primary steed of choice for many Gungans. The exact time the Gungans domesticated the Kaadu is not known. However, xenoanthropologists believe that it occurred in the distant past, as breaking in a Kaadu and decorating its saddle is an important rite of passage for adolescent Gungans. Many of the Kaadu serving as steeds for the Gungans have saddles adorned with enormous Goffbird feathers. It should be noted that acquiring the Goffbird feathers for the saddle is an important part of the Gungan Rite of Passage. More importantly, this ritual is also an elaborate imprinting technique, helping the Kaadu develop an extreme sense of loyalty to their riders.
This loyalty was shown to its utmost extreme when an Acklay escaped the Theed Zoo and ambushed several Gungan Riders while they were sleeping. The Kaadu, to protect their riders, swarmed the Acklay and trampled the beast to death before a Gungan could even grab their Cestas, or throw a Booma. Out of respect to the mounts that died in their defence, the beast's teeth were taken as talismans and are worn to this day as a status symbol amongst elite Gungan Cavalry.