There were other breeds of nexu on Cholganna's other continents, but only the forest nexu had an additional set of eyes able to view in infrared wavelength, which aided in their hunting of bark rats and tree-climbing octopi. They were often exported and trained as security beasts, as used for patrolling on Malastare, or used in arena combat, as seen on Geonosis. Nexu were 4.5 meters long and generally 1 meter tall.
The nexu appeared to be feline in nature, with claws which could slice a Human in half. They had quills along their back, and a long tail that in the wild allowed the nexu to swing from tree branch to tree branch. The tail also split into two equal sections for a better grip on the tree branch they were swinging from. They had extremely sharp instincts and reflexes, although they were known to tire easily, and often used swift movements to finish an enemy quickly, biting down and thrashing their head about to break their victim's neck. Their tongue could be served as a delicacy. Cubs were born pure white.
A particularly stealthy variety was the black nexu; this species was also one of the rarest.
Too vicious to be kept in zoos and difficult to train as watch-beasts, they were instead sought after for arena battles where their ferocity was much appreciated by spectators ( It was the most favored monster). This resulted in many big-game hunters making regular visits to Cholganna, hoping to capture a live nexu for export. Many hunters ended up dead however, when tracking prides of nexu, and as a result fees for live nexus often ranged up to half a million credits per animal. Buyers such as Senator Ask Aak of Malastare and Archduke Poggle the Lesser of Geonosis willingly paid such prices however, in order to add these magnificent creatures to their collections.
A nexu was used during the attempted execution of Padmé Amidala prior to the outbreak of the Clone Wars, and its actions could be considered typical of the species. It would climb towards its victim, strike, then return to the ground quickly, waiting to see if its enemy would strike back. It was an extremely aggressive creature, snapping, clawing and roaring in the general direction of Amidala. When a Geonosian guard attempted to direct it with a blast from his static pike, this only served to irritate the creature further and the guard was quickly devoured. An agile hunter that sacrificed bone mass for speed, a kick from Amidala knocked it down, weakening its tender body greatly. A reek, steered by Anakin Skywalker, finally rammed the stunned nexu, killing it instantly.
After asking for a pet for years, Skywalker and Amidala's great-granddaughter Allana Solo was given a nexu cub in 43 ABY. This was after Leia Organa Solo killed the baby nexu's mother to save an Ithorian, who was under attack from the creature at the Coruscant Livestock Exchange and Exhibition. She named the baby cub Anji.
By 130 ABY, wild nexu were a common and dangerous sight on Coruscant and tourists were advised to stay with their groups when sightseeing on the capital. The nexu were usually seen in areas of the planet still scarred by the Yuuzhan Vong war, a hundred years prior.
Behind the scenes
Art Department concept sculptor Robert Barnes developed the look of the nexu, after several early sketches depicted rather literal interpretations of a lion-like creature. By intermixing different species traits, like reptilian and even human characteristics, Barnes developed an unsettlingly vicious design.
In the non-canon comic book Star Wars Infinities: The Empire Strikes Back, Jabba Desilijic Tiure has a pair of nexu that are later released by the protagonists, instead of his infamous rancor. These nexu ravage Jabba's throne room, and it is later remarked that a better choice for a pet would be something more stable—like a rancor, hinting that Jabba might have had nexu prior to Return of the Jedi. However, this story is an "alternate reality" and not considered canon.