Captain America Comics #31

Hitler's scientists create a bioweapon in the form of man-monster Fungi which releases green mist over America's farm crops to ruin them. Cap and Bucky parachute onto the zeppelin dropping the mist and follow it back into Germany where it plans to resupply the green mist in the swamp that Fungi calls home. Cap and Bucky destroy the creature then hijack the zeppelin back to the states.