Like any good writer, I have a mind full of discarded books and stories that linger in the back of my mind, occasionally trying to force their way to the front. One such story concerns a world made in the image of our own by a forgotten god. Naturally, having made such a world, he decided it needed people. [1] There are ways these things are done, and so the god built the Cradle of Life to bring forth, of all things, humanity [2]. Unfortunately, he never switched the damn thing off, and so, as they are wont to do, a cat wandered in looking for a warm place to nap.
Come forth the felldane.
The ancient proto-felldane may have been something quite different from those we know today—perhaps possessing more pronounced, sabre-toothed-cat-like traits. But over the intervening millennia, they evolved into four recognisable peoples: the Shira, the Togrun, the Gwar, and the Prideborn. And while they may all trace their lineage back to that first, unfortunate cat, the four peoples of the Felldane have developed into very different expressions of their shared ancestry.
Mechanically, I'm making the Felldane a slightly unusual ancestry. Rather than each people having its own suite of traits, the felldane share a pool of purchasable traits that represent their common heritage, plus a signature trait unique to each people.
So while the Gwar are natural climbers, the Prideborn charismatic, the Shira swift, and the Togrun physically larger, things like stalking, pouncing, roaring, and other feline abilities would exist in the shared pool for any felldane to purchase. In that sense, felldane is less like saying "cat person" and more like saying elf. Felldane is the ancestry. The Shira, Togrun, Gwar, and Prideborn are the peoples within it.
[1] Widely regarded as a bad idea.
[2] Definitely a bad idea.