Ace Fenton went on a crime spree in Tombstone, Arizona, wearing a bearskin over a bulletproof suit of steel armor, while wielding a shotgun. Ace led the authorities to believe that a master animal trainer must have been involved, planting a false trail to draw them away from the true culprit. While robbing a Pony Express, Ace had to fight off both the Rawhide Kid and the Two Gun Kid, succeeding in escaping after they ran out of ammunition thanks to his bulletproof steel hide. The Rawhide Kid was believed by many to have been the culprit behind the Pony Express robbery but was convinced by Two Gun Kid to turn himself in for a trial. the rawhide kid was to be defended by Two Gun kid's alter ego, lawyer Matt Hawk. Ace used this opportunity to turn the Rawhide Kid into his scapegoat, trying several times to stir up the locals against the Rawhide kid, claiming that he was obviously the Grizzly's trainer. To further implicate rawhide kid, and prove his claims, ace broke the Two Gun Kid out of the court room during his trial, but Rawhide outfought the Grizzly and forced him to flee. Again joined by the Two Gun Kid, Rawhide kid tracked down ace and tricked him into confessing that he was indeed the Grizzly. The pair captured ace after a gunfight and turned him over to local sheriff Brett Barton.