Final answer:
Germany introduced poison gas as a new weapon in World War I, causing mass casualties and fear among soldiers.
Step-by-step explanation:
The new weapon that Germany introduced in World War I was poison gas. It was first used by the Germans in the Second Battle of Ypres in 1915. The introduction of poison gas was highly effective as it caused mass casualties and created fear and panic among the soldiers on the battlefield.
Learn more about Germany introducing poison gas in World War I