These winged lizards possessed heavily muscled bodies covered by purple scales. Their long necks held small heads with short, wide snouts and sharp fangs. An adult drexl's largest teeth were the length of a Human arm, and the creatures had a stature similar to that of a krayt dragon when fully grown. A fully grown male specimen had a wingspan of twenty meters across. The peculiar orbit of Dxun around Onderon allowed them to migrate to that world.
Drexl began life in a larval stage and were born 3 meters tall. They had no wings in this stage, but were extremely fierce as well as vicious. These drexl larvae were more humanoid in shape with two legs and two arms, three fingered, clawed hands, a tail, and three rows of spines down their back. The skin of at least some larvae was bright green unlike the dark purple of the adults.
Handling a single Drexl was a difficult task, often requiring three riders to accomplish it. One rider was required to focus their handling on the reins and direct the beast, while another rider was armed with a weapon, with the third rider calling out orders to the controlling rider.
In many cases, drexls were immune to the influence of the Force. Darth Bane, however, was able to subjugate a drexl's mind to his own on a second attempt, shortly after failing due to the unforeseen strength of the reptilian's mind, as compared to a rancor's.
In early stages of Onderon history, drexls were feared predators that spread terror, attacking the primitive Onderonian villages and forcing the development of the fortified city of Iziz as the only safe place to live on the planet. The creatures were later trained as mounts by the Onderonian outcasts, who came to be known as Beast Riders.
A drexl larva was used in General Vaklu's attempted political coup to take over Onderon. This specimen was used to break down the shield barrier protecting Queen Talia's throne room. The larva was later slain by the Jedi Exile and her comrades.
Darth Bane was also able to control a drexl when he was trying to get from Dxun to Onderon after his spaceship crashed. Like the first drexls were able to do, he traveled from Dxun to Onderon on its back. Once he arrived on Onderon his drexl, being much larger than his opponents', defeated the beast riders that were harassing Darth Zannah, his apprentice.