Most claws are nasty, but probably not as hard as steel and still part of your body...so parrying with them is iffy almost universally.
If you feel the need for big metal claws and want the ability to parry with them, either take Athletics and re-flavor it a bit, or if you want to defend with Fists, get Footwork, and re-flavor that instead. There's already a stunt to do what you want, just rename and reflavor it to reflect your desired special effect.