Pantheraptors are large carnivores native to the Federation jungle world Pandora, having been introduced and acclimatized to numerous other jungle planets in Federation of Mankind and Imperium of Sidhae since their discovery in early 22nd century. Presently, numerous sub-species of pantheraptors exist on dozens of planets with climates ranging from jungle to dry shrubland, most of them genetically altered to adapt them to their new environments.
The original Pandoran pantheraptor is easily one of the largest terrestrial predators in the explored galaxy. Standing over 3 meters tall at the shoulder and growing to a length in excess of 10 meters, the Pandoran pantheraptor (the particular species also known as "thanator" in the Federation, and "palulukan" by the native Pandoran humanoids) is an immensely powerful beast with an appetite to match. The derivative species of pantheraptors vary greatly in size, the smallest being no larger than Terran jaguars. In principle, the size of the pantheraptor species in question depends primarily on the gravity and atmospheric oxygen content of their host world, the pantheraptor's world of origin Pandora having a low-gravity high-oxygen environment. On more Earth-like planets, pantheraptors generally tend to be considerably smaller than their Pandoran parent species.
Like most fauna of Pandoran origin, the pantheraptor is hexapedal. It is speculated that hexapedality evolved in Pandoran wildlife for better traction in the low-gravity dense-atmosphere environment. Each of the creature's six paws is armed with powerful claws that enable to tear apart it's prey and scale cliffs and trees. The body is very muscular, lean and covered in a thick and extremely durable skin with underlying bone armor plates. This skin and bone is extremely durable due to naturally-forming carbon nanotube mesh (not unlike that artificially engineered into Sidh skin and bone for the same reason), a characteristic feature of Pandoran megafauna, being impervious to most small arms fire. An adult pantheraptor of the larger species can survive even multiple blasts from autocannons and Sidh energy rifles at least long enough to attack the hunters. Pantheraptors are usually black, this colouring and their general feline appearance and manner reminding of Terran panthers, hence their name.
Like most Pandoran wildlife, pantheraptors have a highly complex respiratory system that enables it to thrive in a variety of environments including ones with a lesser oxygen content than it is naturally accustomed to. The creature's respiratory tract opens both to the mouth, enabling it to breathe and vocalize like most Terran creatures do, and also to four breathing holes somewhat reminiscent of jet turbine intakes opening in pairs next to the raptor's first pair of shoulders. The complex multi-chambered lungs allow the creature to simultaneously inhale and exhale using these orifices, allowing for a much higher and prolonged physical exertion than would be possible for most Terran lifeforms with simpler respiratory systems. Scientific observation seems to indicate that pantheraptors and other Pandoran creatures breathe mainly through their mouths when idle, switching to the more efficient "intakes" when exerting themselves, such as when chasing prey or fleeing predators. The said orifices are also one of the few weak spots on the pantheraptor's tough body, but their placement and relatively small size related to the body makes them a difficult target to hit. Pantheraptors and most other Pandoran beasts lack nostrils, instead perceiving scents with a sensory organ in their palates.
The pantheraptor's head is armed with a very powerful and complex pair of distendable jaws, featuring an outer serrated beak-like structure for crushing the thick armor plating of other Pandoran beasts, and semi-retractable teeth on the actual jaw inside. The pantheraptor's huge dagger-like teeth are ones of the largest among known carnivores, being as long as 23 centimeters in the larger species. Like most Pandoran beasts, the pantheraptor features two pairs of eyes, a prominent luminiscent primary pair that provides the creature with excellent vision, and a smaller set of inconspicuous secondary eyes further forward that provide the creature with UV/IR vision, making it a superior tracker and hunter at any time of the day. The pantheraptor's head is encircled by an array of 10 colourful sensory stalks that function similarly to a cat's whiskers and can also be flared up in a threat display along with four cartillaginous sensory flaps that are often mistaken for the creature's ears (the actual ears being rather inconspicuous orifices on the sides of the skull). The two longest of the sensory stalks contain neural bundles that theoretically allow the creature to interface with Pandora's planetwide neural network - a feature shared by all Pandoran fauna and believed to be a product of intelligent design sometime in the distant past. The purpose of the sensory flaps is disputed, but is believed to be related to echolocation, allowing the pantheraptor to hunt even in complete darkness. It is believed that in favourable conditions, a pantheraptor can sense potential prey as far as 11 kilometers away.
The creature's long, broad tail is internally armored like much of the rest of it's body, and can be used as a powerful weapon to bludgeon the foe in case the three pairs of claws and the massive jaws aren't sufficient.
Pantheraptors are solitary ambush predators, rarely straying outside their established territories. They mate once a year and give birth to a litter of 2-4 cubs. While viviparous, warm-blooded and placental, pantheraptors are not classified as mammals, lacking mammary glands and instead feeding their young with regurgitated meat straight from birth until they become old enough to hunt by themselves. Pantheraptors are very territorial, viciously attacking any creatures including humans and Sidhae they perceive as competitors. Predictably, mother pantheraptors with cubs are even more dangerous, being fiercely protective of their litter. Regardless of the exact species and world they are found on, they are almost invariably the apex predators of their environment. The only credible threat to an adult Pandoran pantheraptor is it's avian counterpart, the great leonopteryx, but the likelihood of a violent encounter between the two is minimal due to their different habitats, the great leonopteryx also being at a distinct disadvantage if it ever strayed into the dense forest undergrowth where the pantheraptors usually prowl. The occasional incidental encounters between the two giant carnivores have usually occured in open areas, the creatures fighting over carcasses of large beasts. In all observed encounters, the pantheraptor emerged victorious if seriously battered, marking it the undisputed king of the jungle that a leonopteryx can only take by surprise.
Various species of pantheraptor exist on worlds other than Pandora, notably the Sedekeen pantheraptor, which rivals it's parent in size and power and the small jaguar-sized Scatachan pantheraptor, which inhabits the arid shrublands of Scatach Prime and is notable for it's immunity to the toxic and highly irritating sap of burnsap shrubs. At least a dozen other species, all artificially-adapted to their respective worlds, exist on other Imperial and Federation planets.
One may wonder why anyone would even want to introduce a predator as powerful and dangerous as this to another world. The answer to that question varies, depending on the world and species in question. On some, like Sedek, they were introduced to replace extinct native carnivores and stabilize the ecosystem. On others, they were introduced as a game species (understandably being very popular among big game hunters for the challenge and danger they pose) or even as biological warfare agents, serving to hamper enemy settlement with constant threat of predation.
The pantheraptor and it's background is a rather obvious reference to the thanator creature in James Cameron's Avatar universe.
The first encounter between a Frencoverse character and a pantheraptor takes place in Access Violation, where Visarion Tokarev is ambushed by the small (if still jaguar-sized) Scatachan variety of the creature, successfuly killing it with a combat knife after a protracted struggle.