The thanator is the rainforest's most fearsome predator. Reminiscent of a Terran panther, this enormous, powerful omnivore is unique in its ability to lord over its territory and strike fear into the largest and fiercest of Pandora's creatures. The Omatikaya, who are renowned for their courage, are shaken by the thanator’s approach, and do not celebrate it in dance or song.

The predator's senses are so highly developed that it can detect prey up to 8 miles (13 km) away. While their hugely powerful jaws filled with long, razor-sharp teeth are perfect for tearing flesh, its armored tail can deliver equally as lethal blows. Furthermore, anything a thanator decides to chase down has little chance, as it is also one of Pandora’s fastest land animals. In a matter of seconds, its six legs can burst into strides up to 40 mph (64 kph), and it is also incredibly agile.

Perhaps the animal’s most unusual feature is its crest of ten sensory quills, two sprouting from each armor plate encircling the back of its skull. The function of these quills is not fully understood; they may be a threat display and also a sensory aid that helps the thanator pinpoint the location of its prey.