"A Taste of Their Own Medicine"
Major Thorpe (writer and artist), Mort Leav (pencils and inks)
Published in Jumbo Comics #45, Nov 1942 - 8 pages
In the Far East observing a battle with the Japanese, ZX-5 see the enemy using poison gas. The make-up of the gas is vital to finding a way to counter it. He decides to head there to get it himself. He uses his disguise ability to make himself look Japanese.