Tell me, is the idea of fire creatures from Mount Thunder new? Of course not; the Fire-Lions that rescued Berek were mentioned very early in LFB.
Is there some relationship or essential similarity between the chaotic-evil skurj, and the "good" (albeit mostly hibernating) Fire-Lions?

(BTW, did SRD ever in any way confirm skurj = threat Kassy blocked = fire-worms in Linden's vision?)