King Cobra is really a variation of Viper but worthwhile in itself.
Aid the 1st pitch of Viper via a sketchy string of eight or ten fixed heads right off the deck. Belay after reaching the far more secure crack above. From here, continue up the crack, but before Viper switches cracks out to the left, head up and right on King Cobra. The next 30 feet or so contains a few fixed heads and climbs through a beautiful, clean headwall with some fixed RURPs. Eventually you will reach a flake/crack system that heads up right to Crack of Fear's 2nd belay.
Rap from here or continue up the 10a offwidth.
Bring your usual clean aid rack. a clean aid ascent of this route relies on a few fixed RURPs.