Nightsabers are the traditional mounts of the Sentinels, and about as common among the elves as a riding horse might be in a human city. Also known as nightsaber cats or nightsaber panthers. In combat, a nightsaber cat is a deadly foe, leaping from the shadows to rend its foes with its fangs and claws.
Before they were domesticated by the Sentinel Army and trained as mounts, Kalimdor's savage nightsaber panthers were considered to be among the continent's most vicious inhabitants. While many of these grand predatory beasts still prowl the dusky shores and forests of the night elves' homeland, the finest pedigrees of the species, recognized by their superior swiftness and agility, now serve a more practical purpose for those skilled enough to ride them.
From the few examples we see involving Tyrande Whisperwind, we can assume that Nightsabers live for a very long time. Ash'alah, Tyrande's mount has apparently lived for over 10,000 years, and Shy-Rotam for at least 4,000. Whether this applies to Frostsabers specifically, or all Nightsabers is unknown.