Terapusmordax is a huge bat-like flying rat and possibly one of the largest flying mammals of all time. It is the largest member of the Volucerattidae, the family of winged rodents peculiar to Skull Island, and the convergent replacements to both bats and pterosaurs. As bats have strong sensing ears, Terapusmordax have the same but perhaps even more advanced. When anything comes close to a Terapusmordax they would make them as their victim. It has a body-length of 3 to 4 feet and a wingspan of 8 to 10 feet. It feeds on almost anything, including birds, lizards, rats, small dinosaurs, and other flying rats. But unlike the rest of its carnivorous kind, it is especially omnivorous; it will eat fruits and nuts. Their common prey are their smaller relatives, Volucerictises, and the flying theropods Vultursaurs, which they catch at dusk. Like its smaller and wingless counterpart, the naked mole rat, Terapusmordax is totally hairless, with translucent naked skin and strong bones for its size. A highly agile flyer, they are able to easily keep up with much smaller birds and flying rats. They dwell in huge uplands caverns, roosting there by the hundreds in colonies ruled by the elder females. The males live in small colonies of a dozen or so and fight constantly among themselves, with injuries and death to infection common. The most notable feature about the Terapusmordax is its eye-watering stink. Its waste contains chemicals that cause an incredibly pungent reek, and since waste often is caked and smeared on the animals, they also tend to smell, regardless of where they go. Interestingly, this smell serves to keep predators away, as it is far too strong for many to deal with.

In the King Kong video game, it is shown that they follow large blue-skinned Queens, and like also in the movie, they are extremely dangerous, and would hunt for humans if ever spotted. They also attack larger animals if ever disturbed.