Granny & Daffy refer to the Nazi airship as a blimp. It is in fact a zeppelin - zeppelins have a rigid internal frame, while blimps are essentially self-propelled balloons, with no internal structure.
Germany was the World leader in zeppelin technology during World War I and the inter-war period, until the Hindenburg disaster. By World War II, zeppelins were obsolete and had been abandoned entirely.