Serving with the 102nd Infantry, 26th (Yankee) Division, Sgt. Stubby was a pit bull mix who snuck his way onto the battlefields of World War I in France and became the unit's mascot. Shortly after arriving, Stubby's unit was hit with a gas attack. After that, Stubby — with his keen ears and nose — would alert his unit to incoming attacks to give the men time to put on gas masks.
Stubby became an ideal search-and-rescue dog. He sniffed out a German spy, earning him a promotion to sergeant, the only dog ever to receive such a promotion through combat.