Sgt. Chesty XII, the official mascot of Marine Barracks Washington, stands at attention as his retirement certificate is read during his retirement ceremony at Marine Barracks Washington, July 25. Chesty served for 40 dog years as mascot. - Sgt. Chesty XII, the official mascot of Marine Barracks Washington, stands at attention as his retirement certificate is read during his retirement ceremony at Marine Barracks Washington, July 25. Chesty served for 40 dog years as mascot.