The jana-nimr were the size of an average hunting cat, measuring 6–7 ft. (1.8–2.1 m) in length. Most of these cats were colored with short gray, black, or sandy-colored fur. However, rare individuals with black-striped gray or yellow fur were spotted from time to time. Their large wings spanned 15 ft. (4.5 m) when fully spread. The wing color tended to match that of the jana-nimr's body fur.
Though they were peaceful creatures, the jana-nimr were fearsome when hunting. They preferred to attack from the air with tooth and claw. Once engaged, they would only retreat from combat if severely threatened. Even then, the jana-nimr remembered the incident and often took its revenge years later.
Jana-nimr nested in grasslands or hilly country. During the mating season, a male would offer gifts of food to his partner. A typical litter was 1–3 cubs. Cubs stayed with the mother for several years. Jana-nimr had a natural lifespan of 50 years.
Like regulars cats, jana-nimr preyed on other mammals or birds. They preferred live prey, but would scavenge when needed. If captured at a young age, and if enough patience and dedication went into training them properly, a jana-nimr could serve as a mount for whoever trained it. Once given, their loyalty was never lost.