The large creature (upwards of three and a half meters tall and up to five meters long) is singularly designed for frigid climates. Massive layers of fat and thick, dark hair help it absorb and retain heat; a ganjuko is noticeably weakened within just a few hours of being exposed to above freezing temperatures. They have black, brown or dark red coloring, although their beaks and heads can range from red to a brilliant orange.

The animals have incredibly hard external skull plates and beaks, which are reinforced with thickened layers of cartilage, providing it a potent offensive weapon in addition to offering excellent protection for the head and eyes. The beaks are often used to crack open the armor plates of prey, as well as for digging into ice. Ganjukos have retractable cartilage lids to protect their eyes in combat, preferring to fight by scent and sound alone (this has come as an unpleasant surprise to many a safari hunter who had thought to stun the creatures with flash grenades and similar pyrotechnics). Ganjukos are active during day and night periods, but take a number of brief "naps" during a normal planetary day/night cycle. Each ganjuko carves out a lair in the snow and ice sheets.

Despite their immense mass, coming in at well over 600 kilograms, they move surprisingly fast. They can outrun most Humans, although their bulk makes it difficult for them to turn and maneuver quickly. Ganjukos are solitary animals, each one controlling a fairly large amount of area (upwards of 200 square kilometers). They have few natural predators as adults; the hatchlings are almost helpless and they suffer a high mortality rate due to other predators.

Ganjukos can live up to 110 standard years old, but generally will only lay four to eight eggs in their lifetime. Their biology indicates a primarily avian heritage, but they share several marsupial characteristics, including a small pouch on the back where suckling young are kept until they are strong enough to fend for themselves (normally about three standard months). Young ganjukos will remain with a parent for up to seven standard months. However, as soon as the young ganjuko begins showing signs of independence (for example, hunting on its own or straying far from the parent), young are cast out and forced to fend for themselves.

Ganjukos have a deserved reputation for being dangerous and easily angered animals. They are the subjects of numerous safari expeditions, but many new hunters underestimate their speed, cunning and ferocity - the ganjukos have claimed more than a few "trophies" themselves. Ganjuko beaks are often carved into highly prized and expensive dagger blades (which are quite popular among wealthy Bothan clan leaders).